Being My Brother-in-Law's Substitute Luna

Mary's POV

Helping my twin sister has always been my priority right from when we were kids. What she asked me to do recently is what I'm still wondering, if I can opt in or not.

Lucy, being married to the Alpha Prince second-in-line of succession, Prince George is quite bound by some rules pretending to the royal family. She can't attend unsolicited events, coupled with the fact that she has a baby son whom she takes care of with her husband. Prince George doesn't need a maid, so she has no choice but to take care of her son by herself.

Last night she called me, informing me of a friend's birthday party she wanted to attend. I can remember furrowing my eyes while listening to her, even though we were on call.

"Are you sure this event is quite suitable for you?" I asked her about the rules anyone in the royal family of San Marino had to follow. This was from what she had been telling me and from what I heard on the television.

"No, it's not permitted, of course you know but I want you to sneak into my house late in the evening before my husband comes back from work. Just pretend to be me. You will return in the morning before he wakes up, I'll be back by then."

"Oh my goodness!"

"No panic, no worry," she rushed over her speech. "You know how identical we are in appearance, the color of the eyes, voice, and hair. He wouldn't detect it."

"I'll tell him tonight I just want a day off without being touched by him, a day off breastfeeding our baby directly, I'll use a feeding bottle with my squeezed breast milk instead. Any conditions appropriate for your stay with him, I'll do it."

"Hmm," I swallowed the saliva in my throat.

"It's alright but is this party important?" One mind was dragging me from going in for this risky task while another was urging me to help her as I'd always helped. But still, I wanted to know how important this party she wanted to attend was.

Prince George is the one sponsoring my studies and my master's program in college. He is likewise the one taking care of me in general being his mate's sister and I know he's doing this because he and my sister are together. Anything I'd do to make them still together, I'll know all there is to lose if they should separate. Aside from this, I love my sister so much. Even though I'm still single, I'm happy having a sister like her, who's a princess by marriage. This would make me opt in for this task, even if I'd never do it.

"My best friend in high school and college is celebrating their first birthday after moving to San Marino. The one who helped me push up with my grades and as well saw me all through the difficult times."

"Well, that sounds like a justifiable excuse." This is how it sounded in my ear, especially her last statement. "Okay, I'll do it!"

This person was good to her and she can at least repay him by celebrating with him. She has been telling me of this wonderful person each time she recounts her life in high school. We happened to gain admission into different schools.

"Wow, wow! Thanks so much, Mary, for coming in through for me, you're such a darling!" I could hear her blowing several kisses on me over the phone, I could even hear her jumping around. I wondered if her husband wasn't around, so I couldn't afford to ask.

"No, he's always back from work at 7 PM nowadays." He is working as a senior doctor at the Royal Medical Center, close to the palace, which isn't so far from the private apartment they live in outside.

"Oh, that's nice." I'll memorize everything in my mind, including the likely conversations that might kickstart while with him and how to respond.

"Till tomorrow!" I say at last before ending the call. I get in for a little pride since I will be the one to help her. I know Lucy, she will smile at this.

*******

Seeing the most eligible bachelor sitting here right in front of me in my white net maternity gown with my bra and pants see-through made my hormones high. Louis, the five-month-old son of my elder sister is breastfed through his bottle in my hands, I'm shaking right inside of me but I try my best to compose myself.

This man is fucking charming!

Just as his position says.

"Oh God, don't let me be exposed!" I pray inside of me, my heart is beating so hard right now. Something whispers into my ear, "You're his mate for the night, behave as one."

I take a deep breath. Then look right up at him. His radiant blue eyes shine over me with lust. I want to question him but then I recall after all I act as his mate.

"Have you forgotten about what I told you yesterday?" I slightly frown my face to know that I'm serious. He grins so quietly, in a sinister mood which is interpreted to mean he wouldn't be sticking to what was agreed on.

"I'm the Prince, my mate can't be detected when I'm to touch her and when not to. I'm horny, either fuck me tonight or I go out there and fuck. I'm a man, so I know how intense it can be. I have many girls out there at my disposal, just that I choose to be faithful to you."

My mouth becomes mute. I can't react to what he just said. I know it's nothing but the truth. I have no defense.

"Why punish me for no just cause, are you sick?" He leans to ask me and I shake my head.

"Should I go out there and find someone more romantic than you, you right know what will happen to our marriage." His tone was sarcastic here, but I know he can be tempted to do it.

I narrow my eyes, thinking about this again quietly. "Is he really serious with what he's saying right now?" I ask myself.

"Who wants to take chances?" A voice was speaking through me, and I shuddered. "Remember you are Lucy right now, he sees you as his mate. Refusing will give him a second thought. Why don't you accept it?"

My mind is working up a lot of thinking at this moment. "Why me? Why must this happen?" My eyes turn dull and my head turns. I came here to represent my sister, you act like she's the one, being that I know about almost everything that happens in their life being sort of a counselor to her as a caring twin sis, I wasn't too scared of coming here although I was initially.

Prince George's asking me for sex now is the serious challenge I'll be encountering. I don't want to cheat on my sister with her husband, one thing that made her tell me yesterday she doesn't want him to touch her today knowing fully well she wouldn't be the one present.

"Are you in for this or not?" The prince asks, his voice both stern and gentle at the same time, a dangerous combination. I swallow the lump in my throat. When I didn't say anything, he asked further.

"You don't feel like having me touch you, have I failed to be your husband today?"

"I... I....don't worry." I pushed forward to him so his hands could reach me. This marriage is special to my sister and me as well. I know the great things George has done for me as a sister-in-law. Aside from this, having a sister who is married to the prince is something to cherish and protect. I didn't want my own decision to crash her marriage, she might never find someone like him again and I'd be lost, I'd go bankrupt, I'll have no one to take care of me.

His hands pulled forth in front of me, caressing my soft boobs as I was in Lucy's lace bra. I raise my head, trying not to enjoy, not to fall for the sensation that's climbing up my body. He squeezes me hard, then slides his hand inside my right boob, nibbling at my nipple. My core is pulsing right at this moment.

I watch as he pauses all of a sudden, taking the baby away from me, and going over to his cradle to lay it to sleep. Then he returns to the bed, sitting right in front of me, he pulls up his T-shirt and then his boxers, setting eyes on his huge cock which was already aroused because of me makes me shut my eyes briefly.

"I'll be taking you to cloud nine, my charming, sweet mate!" He extends his hands right across to carry me up.

No! No! What if Lucy returns to know we had sex, wouldn't she see me as a traitor? Or is there something I can do right at this moment to avoid it?

Mary's POV

This is my brother-in-law, I'm not supposed to be doing things like this with him. Before I could utter any word, his hand pulled inside of me once again. After touching my boobs to his satisfaction, he goes over to pull off my net gown, leaving me only in my bra and panties.

I can feel it, I'm badly wet down there.

"Gosh!"

What a great temptation! Getting wet for my sister's husband.

He slides his hand deep into my pants causing me to groan, both in disappointment and pleasure. I close my eyes tight shut when his finger slides in.

"Hmm, hmm," I try suppressing the moan, this is my brother-in-law.

He can't get comfortable with the way we are going so he proceeds to pull off the remaining piece of clothing on me, my bra and pants. I'm bare-baked right in front of him, his eyes savoring my body like a wild animal savoring his prey.

"Gosh!" I can feel his lips on mine, my eyes are closed. The next second, his lips sink into mine and he begins to kiss me. "What a fucking sweet kiss!" I was now battling between resisting my sister's husband and pleasure. This guy is putting me in bliss.

His hands fondle my boobs as he's kissing. "Gosh! You're fucking sweet!" He moans while kissing me. His lips begin to trail from my lips, going slowly down me, stopping at my cleavage to suck my boobs. I can't explain what I feel at this moment. The sensation as he keeps sucking my nipple gets me moaning all through, from my right nipple, he progresses to the left, sucking and nibbling both at it, at the same time. Pinching it with his teeth makes me hitch. My core gets more wet.

"Ouch.... Oh my goodness!" I can't suppress my moan further.

George takes down his lips, stopping once again at my navel where he sticks out his tongue and nibbles at it.

"Aww... Aww..... "

Look at me! I was asked to come pretend like Lucy, only for me to be enjoying romantic sensations from her husband, who thinks she's the one, with me doing this as well just to save her marriage. I just wish this would be hidden from her, or else she would never trust me again, she might not believe that I'm doing this because of her husband's threat.

As his lips get down, he widens my leg. It gets into my mind at once where he's heading. "I'm gonna eat your pussy, my sweet pussy!"

"Fuck!" His words make me so wet and aroused. I'm getting out of control, I don't think I can control myself any longer. His tongue plays mildly on my clit, while he raises his eyes to watch my reaction. My lips are round and open, moaning, my eyes slightly closed.

"Oh fuck! I'm dying with passion!" I moan and groan, wishing him to suck me harder, his fingers slide in, and while eating my pussy, he's fingering deep into me, a second-hand joint making me gasp for breath, and worse still his third finger.

I'm getting drained of all my energy.

"Rise!" He orders after making me release, I'm still moaning, and I rise slowly, still gasping from my release. I fall back on the bed, spreading my legs wide while touching myself. The release gets such a sweet sensation.

"Please.....Please," I chuckle nervously while breathing hard. He looked at me with amusement, he was patient to wait as I kept spilling out light drops of my whitish fluid. Only then did I rise.

"Kneel!"

I get down on my knees, he's stroking his cock. My second time getting in contact with his cock. I see the stars as I gaze at them, so big, long, and turgid.

"Gosh!"

"Suck it, baby!" I didn't waste time but pulled my lips close to his balls, starting it by kissing around it, trailing my saliva over to make it lubricant, I placed sweet kisses around it, before pulling my mouth deep into it. He grips my hair, gagging me with his cock.

"Awww!" I gasped, enjoying the ride all along.

"Thrust harder! Awww..... " I hear him moaning, I sense he is enjoying the ride. I'm gradually getting to flow with so much speed, moaning all the way.

"Hm-mm, hmmm." He moans. This keeps going on for more minutes, I wish I could continue this way all through.

"I want to cum, I'm gonna cum!" He says in between gnashing teeth.

"Awww..... " I keep moaning. He spills his fluid on me, draining it across my cleavage, his moan, especially at this moment makes me go all crazy. I breathe a heavy sigh of satisfaction, I watch as he holds his cock and strokes it to release more.

As we climb up on the bed, my heart shakes, my breath increases. "What if he gets me pregnant?" I'm not with any pill here, neither is he with a condom, of course, he wouldn't use that with his mate. I'm slightly nervous.

I can't show it but deep inside of me, I'm shaking. He teases his cock over my clit, then pulls me straight right inside of me.

I gasp.

He starts to pull in, slowly and steadily, filling me with deep sensations, and sending me moaning all the way. I'm climbing steadily up the ladder of this bliss when his phone rings. The name pops up.

"Prince Alex!" This is his first brother, the next Alpha King. From what I've been hearing from my sister, he's quite talkative and witty and loves creating problems between the royal family members, making him a little bit unfit for the throne. At times movements in parliament to have George in his place come up but the original tradition demands the firstborn to take over as Alpha king of San Marino after their father who has a few years left to hand over.

"What's it with him? He must have some serious news, my brother rarely calls me, at least it's something critical."

"But he's talkative?" I ask.

"Not with me, we are rivals. He only calls to deliver bad news, sorry to say this. That's just the truth, not trying to blackmail him as he does with me."

"Hmm," I sigh, jerking my head.

I watch as he picks up the call, his cock still inside of me as he's on top of me. "What!" I hear him shout, and his eyes widen. I shudder.

"What's it?" I force the words out.

He immediately places the call on the speaker. "I'm with your mate here, Lucy! She's so drunk at this birthday party. She asked me not to tell you about her whereabouts!"

"My mate? But my mate is here!" George replies with great shock. He turns to look at me with doubting eyes.

I raise my hands to cover my mouth in shock as my eyes get so wide. "Oh God! I'm caught!" Everything is out! I'm shaking so hard now with fear knowing I'm dealing with a strict, no-nonsense Prince.

George's POV

"Who are you?" I quickly pull my cock out of her, staring deep at the woman right in front of me. I know my mate has a twin sister but I didn't just expect what I'm hearing.

"What if Alex is trying to destroy your marriage, how can your mate do this?" My mind brought me to consider this, so I decided to give it a second thought.

Since I paused the call, I tapped to return to the call just to continue talking with Alex.

"Can I get proof that it's my mate and not her sister?"

"Sure, since you don't want to believe me." I get to hear the audio clip affirming what he's saying. I guess they were sitting beside each other or Alex saw her and decided to walk up to her.

"I'm sorry, Alex. I wish you wouldn't tell my husband what I'm gonna tell you." There's a heavy breath from her end, showing she's drunk as Alex said. "My boyfriend right from college is new in town, right from college we've been dating, in an affair with him...... " She breathes heavily again.

"George thinks he owns me solely, not knowing I have someone I love so much, he has always promised to marry him. Even when I'm married, I can't leave him. Glad he's here in San Marino."

I want to stop the clip, I can't hear more of this, it's hurting me deep inside but then I hear her mention something about her sister.

"I had my sister sneak in pretending to be me. Mary will pretend before my husband as though I'm the one till I return......."

"Oh gosh!" I scream so hard, ending the call. I've gotten all I need to know. Turning to Mary, my furious eyes cascade over her.

"So you're in this plan together with your sis, you make me sleep with you. The sister-in-law I take so much good care of? I'm honestly disappointed in you!" I bark at her, causing her to shudder. She begins to slowly move back out of fear.

She falls to her knees, tears start to stream from her eyes. "I'm so sorry," she pleads. "I wouldn't have let you touch me if you didn't threaten to go out there and find some other woman." More tears start to stroll down her eyes. "You know how happy I am with this union between my sister and you, I couldn't just use my hand and create separation by refusing to give you what you wanted."

"This is why my sister asked you yesterday not to touch her throughout today, knowing she wouldn't be the one with you." She further adds.

"Oh no, I'd been tricked!" My mind takes me back to that yesterday, I saw her squeezing her milk into Louis' feeding bottle. She also asked me to refrain from touching her today, even when she seemed to be reluctant at first to me touching her this evening, which I should have suspected. My mate is always eager to get me to touch her. She loves me.

"This is all my fault!" I raise my hand to my head, scattering my hair in frustration. Aside from deciding to be faithful to my mate out of love, it's to uphold my integrity. I'm a prince, I don't want a situation where someone would come out to say something bad about me in the future.

"Who told you that's what I wanted?" I extend my hand, giving Mary a heavy slap. "Why wouldn't you tell me while I was about to fuck you?"

I rise, resting my hands on my waist. What am I going to do now?

My anger fumes against Mary, she's right in on this with her sister, she can't be honest with me for once. So all this while, she couldn't tell her sister to quit her secret affairs? Yet she proves to respect and love me so much for being her benefactor!

"There's no escape route for you, you have to pay for this!"

"No no, I'm so sorry," she pleads, shaking.

"Do you know what will happen to me should the royal family hear this? In case you don't know, I'd be forced to resign from my position, I'd no longer be able to stay with your sister and then what you claim to preserve, my taking care of you will cease. See now you will be the one using your hand to cause your destruction."

I will make her face the wrath of the law. She's impersonating, so she has to face the consequences of impersonating, which is imprisonment. I can't spare her.

"No, wait and confirm before you take action," my mind cautions me. This can look like a whole truth but there's another part I didn't know. "Alex might hide this away from you so you will have a problem with your mate!"

Exactly!

My mind brings these thoughts my way.

I resolve to investigate the root of my brother's report in my heart but turning to see Mary, staring nervously from the wall which she's leaning against, my anger pulls up greatly. I pull out my belt, almost slashing it across her body if not that she dodges.

This is something I've never tried before nor hope to do, how could she make me sleep with her?

Oh my God!

Suppose this news reaches the royal family, she and I would be in trouble. I can't envisage the shame of being exposed. We have been a couple admired by everyone.

I sighed, stamping my feet angrily on the floor, my eyes pointing out lashes of furious gazes on her. My heart was heaving heavily, I felt it would cut off any moment.

"You make me do what I wouldn't want to do!" My breath is going up so quickly and heavily.

"If I ever see you again near me or my house or on my online account, you will see the other part of me people have been complaining of!"

"I'll have you put to jail and will probably execute you!"