Stepsister’s Slumber Party. Mandy has her best friend Valentina over for a slumber party. They’re having fun, teaching each other how to twerk & taking videos of one another. Though Mandy is your stepsister and you know you shouldn’t be spying on her, you can’t help yourself. You love big butts, and both of these girls’ booties are so huge.. The girls catch you spying on them and they laugh at you. But they call you over & ask you to judge which of them twerks the best. Then Mandy tells you it’s past your bedtime & you’d better run along.. But of course you just can’t resist sneaking back into the room. How could any boy resist? You’re pleased to find them making out. Your dick is so hard watching your stepsister & her best friend. You’ve never seen girls making out before. Then they actually start going down on each other! Crazy. They catch you again and laugh at you. But Val suggest they “use” you. Mandy is reluctant at first because you’re her stepbrother, but Val is very convincing. They make you lie down on the floor, pull down your pants, and are shocked to discover your big penis. Shock quickly transforms into lust, and they take turns using you to pleasure themselves..