My little sister, Alice, is coming to visit

Guess I have to put away my lust for now. My sister is coming over for a slumber party, and so I won't be getting any action while I babysit her.

I guess babysit isn't the right word. She just turned 19, and she's a freshman in college, but she's still a baby. She and I were always pretty close growing up, having gone to high school together. Although she doesn't know I'm a lesbian, I've help her through various boyfriends, none of whom lasted very long. We've talking about sex and boys, and in all honestly it'd be good to see her. But again, I'm just so fucking horny, I don't want to be metaphorically cockblocked by my little sister.

My sister doesn't look much like me. She's blonde, with barely an excuse of B cup breasts, compared to my curvy hips. People don't usually think we're sisters, but having grown up with that, I'm used to it.