You ask your sister for help jerking off - you've never done it, but you know it's going to feel so good. You just want to do it right, and your sister has always been helpful with these things. So you ask, and she's ready. Your sister tells you that she has watched plenty of porn and can totally help! She tells you to get your dick out and stroke it, like with a limp hand. You shrug, although it doesn't totally make sense. The other hand grabs your balls. You like that. It feels pretty good, although a little odd in the way she's describing it. But then, she tells you to take your hand away from your balls and... SLAP your dick! She insists that this is what they all do in porn, that you will totally love it. Oh, but it HURTS. And she assures you that if you do it more, it'll feel so good. And well... she isn't totally wrong. More instructions and slapping lead up to the finale, where she tells you to lay on your back with your legs up! Aim your cock right at your mouth and open wide, for a big surprise! This is what she says is in porn, and that you're gonna love cum in your mouth!