Maybe I could do all of her friends so that they could have the experience of doing an upperclassman! I'll break into her computer, send them all an e-mail pretending that I was her and tell them how great I am in bed. That'll make them think that she's into incest too. Boy, would she be pissed when finds out, but maybe I can score with one of her friends before she learns what I did.
Hey, a chance at free pussy is worth having your little sister mad at you for a few days.