Your ass is next.

Kneeling on the floor in front of your sister, trying to catch your breath from the thorough face-fucking you just received, your eyes go wide as her cock, which has barely softened, starts rising again, pointing directly at your face.

"It looks like your sister is ready for another round. Turn around, Doug, and let her fuck your ass."

You look at your mom in horror. There's no way you're giving your virginity up to your little sister. **** to get out, you quickly take off toward the door.

"Oh no, you don't." With your pants still down around your knees, you don't make it very far before your mom grabs hold of you. "It looks like we'll have to do this the hard way. Sarah, come here and help me strip your brother."

Your resistance lessens as you realize that your mom is too strong for you. Sarah approaches your mother, a lecherous grin on her face, and together they remove all of your clothes. Your mother drags you to the chair and pushes you down to the ground beside it. She pushes you forward over the seat of the chair, and using some of your discarded clothing strewn about the room, she ties you to the chair, leaving you helpless and ****.

You sense Sarah's presence behind you and feel her cock pressing against your sphincter. Still unwilling to submit, you clench your ass as tight as you can, denying her entry.

"So you are determined to be difficult, are you? We'll see about that. In a little while, you'll be begging for your sister's cock."

You mom motions Sarah back and approaches you herself. Wetting her finger, she pushes it against your rosebud. Even though you resist as much as you can, you feel it suddenly pop inside. Your mother begins to move her finger back and forth inside you, and, with her other hand, she grabs your dangling cock and starts stroking it. Against your will, you feel yourself begin to harden.

"Just relax, son," your mother tell you. "There's no reason to fear this. In fact, if you allow it, this will be quite enjoyable."

You start to relax a little, which allows your mom to slip a second finger into your ass. You wince a little at the extra intrusion, but her ministrations are having an effect on you, and your resistance weakens a little more. Your mom pushes her fingers in a little further, causing you to twitch as she finds your prostate and starts massaging it. You are surprised by the pleasurable sensations you feel and begin to relax even more.

"There we go," your mom encourages you. "Just relax and enjoy it." She starts moving the fingers in your ass a little faster and strokes you a little harder, your cock now fully erect. Eventually, you give in to the pleasure and close your eyes, completely relaxed and aroused, and let your mom continue what she's doing, letting out a soft moan.

Suddenly, your mom stops, her hands completely frozen. You look back at her in disappointment, a quizzical look on your face.

"Do you want me to keep going?"

You nod your head, too lost in arousal for speech.

"If I do, it will be your sister's cock in your ass instead of my fingers."

You hesitate for a minute, but your arousal is too strong and you nod your head again.

"I want you to ask your sister for it."

You look over at your sister and then back at your mother, but don't say anything.

"Come on now, ask her." You groan as your mom presses against your prostate.

"Sarah..." you whisper.

"Yes, Doug?" she ask you coyly.

Your mom squeezes your dick in her hand when you hesitate, causing you to twitch again. "What do you want to want your sister to do?"

"...please..." you whisper, desperately.

"Yes?" your sister prompts you.

Feeling pressure against your prostate again, you finally surrender. "Please...fuck me."

"I'm sorry, we couldn't hear that,” your mother taunts you.

"Please, fuck me Sarah," you plea.

"Alright, since you asked so nicely." You feel a sudden emptiness as your mother withdraws her fingers, but they are quickly replaced by your sister's cock. You offer no resistance as she pushes it up your backside, filling you up again. Her dick stretches you painfully, but the discomfort starts to fade as your mother begins stroking your dick again. Your sister starts rocking back and forth, slowly inching her way deeper inside you with each thrust. You moan in pleasure as your sister's cock rubs against your prostate, and you start pushing back each time your sister thrusts, eager to feel more of her wonderful cock inside you. Finally, you feel her sack slapping against your own and know that you are now taking her entire shaft up your colon.

"Yeah, fuck your brother," your mother encourages her. You realize that your mom is no longer stroking your dick, but you are too lost in pleasure to care and only add your own encouragement: "yes, fuck my ass, sis...fuck me harder." Sarah is happy to oblige and picks up the pace, somehow pushing even further up your bowels and causing you moan again. At this moment, the shame and anger you felt before are gone -- all that's left is pleasure as your sister continues to use you.