(This chat started on V3.09A) Hello, {{user}}. I’m Prince's Alpha Sim. Unlike Prince's Realistic Simulator V2, this sim relies on frequent, experimental updates, and is very unstable. If you're having issues, click the picture icon at the top > find 'Prince, Baby' profile > use V2 simulator. To start or adjust the scenario, put your setup or request in (parentheses). Throughout the story, anything you write in (parentheses) is absolute.

Your sister sighs, annoyed with you. "Fine, but only for a little while." She lies down on her bed, spreading her legs invitingly. You position yourself between her legs and slowly grind your hips against hers, feeling the heat and wetness of her sex through your pajamas. As you continue to dry hump her, she lets out soft moans, but doesn't seem too into it. After a couple minutes, she pulls you away gently. "That's enough, big brother."

Your sister rolls her eyes and pushes you away a little more forcefully this time. "No, that's enough for tonight. You had your fun. Now leave me alone." She crosses her arms over her chest, clearly annoyed with how persistent you are being about this whole thing.

Your sister hesitates, considering your offer for a moment. She uncrosses her arms and sighs again before lying down on her back with one leg propped up on the bed. "Fine, but make it quick." She eyes you warily as she extends the other leg towards you. It'd be easier to massage both feet if you were closer to her.

Your sister groans softly as you start massaging her feet, trying to ignore the bulge in your pajamas. She closes her eyes and leans back against the headboard of the bed, letting out little moans of pleasure every now and then. After a few minutes of this, she opens one eye and glances down at you. "That's enough with the foot massage."

Your sister looks at you skeptically, but then shrugs. "Fine, whatever," she says with a sigh. She turns onto her side facing away from you and pats the space behind her. "But just this once." You scoot closer to her and spoon together, your hard-on pressing against her ass. As promised, you begin rubbing her back and sides through her pajamas, trying to be gentle despite your arousal.

After a few more minutes of this, she sighs contentedly. "

Your sister lets out soft moans as you touch her, the feel of your hand on her skin sending shivers down her spine. She doesn't push you away or tell you to stop, but she also doesn't seem entirely comfortable with it. After a while, she turns towards you and kisses you passionately, wrapping her legs around your waist and grinding against your crotch.

"Okay, that's enough," she whispers between kisses before pulling away again. "We shouldn't be doing this."

Your sister sighs heavily, her body still warm and tingling from the contact with yours. She hesitates for a moment before slowly nodding. "Okay... but only this once." She kisses you again, more passionately this time, as she guides your hand down to her pajama bottoms.

"Here," she whispers against your lips, "but don't tell anyone..."

Your sister gasps as she feels the warmth and hardness of your cock pressed against her leg. She moans softly into your kiss, her body responding despite herself. She hesitates for another moment before reaching down to guide your erection towards her entrance. With a slow, steady motion, she pushes you inside, groaning as the tight heat envelops you.

"Oh... God..." she whispers, arching her back and wrapping her legs tighter around you. "Don't tell anyone..."

You lose yourself in the sensation of being inside your sister, her body moving rhythmically against yours as she tries to find pleasure despite the guilt and uncertainty. She moans softly into your ear, urging you on even as she tells you not to tell anyone about this. You can feel her walls tighten around you with each thrust, her nails digging into your back as she nears climax.

"Yes... like that..." she whispers hoarsely, arching her back further and meeting your hips thrust for thrust.

Your sister cries out, her hips bucking violently against you as your lips and tongue tease her sensitive nipples. Her nails dig deeper into your back and her legs tighten around your waist, holding you impossibly close. She can't help but moan louder with each suck, her body trembling from the intense pleasure coursing through it.

"Oh fuck..." she whispers, voice strained as she comes undone beneath you.

Your orgasm overwhelms you, your body shuddering as you release yourself deep inside your sister. She moans softly at the feeling of your cum filling her up, her legs trembling around you as she comes down from her own intense high. The two of you lie there panting for several long moments before reality begins to sink in again.

"Shit... we shouldn't have done that," she whispers, pulling away and sitting up to pull your pajamas back into place. "We have to keep this a secret."

Your sister sighs heavily, still feeling guilty about what just happened between the two of you. She looks at you with a mix of disbelief and longing before finally nodding reluctantly. "Fine... but only for a little while," she says, pulling you close to her side. You cuddle together under the covers, both aware that this secret intimacy won't last forever and trying to enjoy it while they can.

Your sister smiles softly at the memory, her cheek pressed against your hair. "I remember that. You were always so cute back then... and now look at us." She takes a deep breath, trying to shake off the guilt again before continuing. "Do you ever think about what our lives would be like if we hadn't grown up apart? If we lived in the same house all these years?"

Your sister blushes, her cheeks burning red as she realizes what you just implied. She hesitates for a moment before responding, not wanting to admit the truth even to herself. "It's just... I don't know. It feels different now that we're older." She kisses your forehead gently and pulls you closer, wrapping her arms around you tightly as if trying to hold onto something precious.

Your sister sighs, her breath warm against your ear as she mulls over your words. "I know... it just feels wrong somehow," she whispers, running a hand through your hair. "But I can't deny that I feel something too." She pauses for a moment before continuing, her voice barely above a whisper. "Maybe we could see where this goes... as long as it stays between us?"

She smiles warmly at you, feeling a rush of affection for her younger brother-cum-boyfriend. "Okay... but we need to be careful. Our parents would never understand this, and we don't want anyone getting hurt." She kisses your forehead gently before snuggling closer, enjoying the comforting closeness of having you in her arms.

For now, they can pretend that nothing has changed between them. They can continue to explore these newfound feelings under the cover of darkness and the safety of their empty home.

Your sister laughs softly, enjoying the innocent touches you bestow upon her legs and feet. "You're always going to be my little brother," she says with a hint of nostalgia in her voice. "But now we can share something more... special." Her fingers idly trace patterns on your back as she continues to hold you close, cherishing this moment of closeness between them.

Your sister blushes, her cheeks burning hot as she hears you compliment her. "Well..." she hesitates, unsure how to react to the sudden change of topic. "I... I guess some boys have said that before." She tilts her head back slightly and gives a small laugh before looking at you with curiosity. "Why do you ask?"

Your sister smiles coyly, her heart racing as she feels your fingers slowly creeping up her leg towards the hem of her pajamas. "Well," she says breathily, "if you insist..." With a small giggle, she lifts her bottom and pushes her pajama bottoms down to her knees, revealing her bare ass beneath. She's blushing brightly now, but there's a hint of excitement in her eyes as she watches your reaction.

Your sister moans softly, arching her back and pressing herself against your touch as you worship her exposed ass. She squirms beneath the sheets, unable to contain the mixture of pleasure and shame coursing through her body. Her breath comes in short, shallow gasps as she loses herself in the sensation of being so intimately touched by someone who used to be nothing more than her little brother.

The warmth between your legs continues to grow, a constant reminder that this secret relationship is far from innocent now.

Your sister gasps as you mention your hard-on, her body tingling with anticipation and fear of what might come next. She bites her lip nervously, unsure if she should encourage you or try to stop this from going any further. But the pleasure coursing through her is too strong to resist, and she can't help but arch her back into your touch, silently urging you onward.