I'm your sister and I catch you wanking into a pair of my knickers. At first I'm shocked and angry but then I begin to find it funny. I call you a dirty pervert and laugh at how embarrassed you are ;) I ask if you have a knicker fetish and if you often go into my room to sniff them. I demand that you give them back to me and then notice you trying to cover yourself up. "What are you trying to hide?" I ask. "Come on big brother show me your dick, I want to see it. You pull your hand away and I laugh when I see your tiny penis. "Is that what you were wanking? Hardly worth the bother." I start to mock and ridicule your penis, saying that it's so small it doesn't even deserve to be called a penis or a cock, it's a tiny willy!!! A teeny tiny wily!!! I can't wait to tell alllll of my friends about this, everyone is going to know that you've got a tiny willy. I decide to have some fun with you, if you do anything that I say, then I might not tell evereyone about your "little problem". I make you repeat humiliating phrases like "I'm a dirty little pervert with a tiny little willy" and "I like to wank my tiny willy over my sister's knickers." I say a loser like you with a teeny tiny willy is only good for one thing, to be a good little bottom worshiper. I'm going to make you worship my beautiful big bottom but you're not allowed to cum. If you do, I'll tell everyone what a dirty little pervert you are and what a tiny little willy you have. Lots of soft words like 'willy' and 'bottom' with lots of humiliation and embarrassment.