Your sister

As you step into the hall, you spot your bikini-clad sister Julie walking up the stairs. She's whacking at her hair with a towel, drying off from the pool as she heads toward her room.

"Hey, cutie," you say, stepping towards her. She cries out in surprise as you grab her by the shoulders and press her against the wall face-first. As her well-learned instincts kick in, she drops the towel and braces herself against the wall, spreading her legs and presenting her ass to you.

You reach out and spank her lightly, chuckling to yourself. "Well, I wasn't going to fuck you right now, but if you insist..." Lining your hardening cock up with her, you pull her bikini aside and slip into her wet lips.

"Fucking finally," she moans with pleasure, biting her lip as you push deeper. "You really know how to keep a girl waiting, you know that?"

As you both reel in ecstasy, you can't help but groan along with her; although the double blowjob was far from normal, this is the first incestual sex you've ever had...and you're loving every second of it. Picking up the pace, you reach around to cup one of her round breasts.

"Fuck your little sister like the slut she is!" she cheers you on with an excited squeal as you increase the **** of your rhythmic slamming, pushing yourself in as far as you can.

Tweaking her nipple through the damp bikini top, you lean over to whisper in her ear; if sex is no big deal in this world, this seems as good a time as any to chat with your sister about the big plans you have for tonight.