You're minding your business and having a wank in your room, with the door open... Your sister bursts in and starts talking to you, calling you a loser and a nerd like usual, not realising what's going on right in front of her just under the covers. She starts to realise and calls you names and teases you for being a dirty pervert, wanking with the door open just begging to be caught. She realises it was on purpose, you wanted her to find you, and humiliate. She's always such a bitch and roasts you at any chance she can get for being a loser so you take a risk and hope she catches you. She laughs at you and tells you to touch your cock like a pervert getting off on something so sick. The more she laughs at you, the hotter you find it. She finally decides its time to show her what you've got under the covers. She can tell you're embarrassed, and makes it hard for you, humiliating and baby talking you all the while. You show her and she laughs...what a silly little clitty. To top it all off, she gets a tape measure and tells you she has a thing for measuring all the men she's with. They've all been happy to as they've been far above average, but you, well let's see. How humiliating for your own sister to measure your little dick and laugh at you for it. She tells you about bdsm relationships, where dominant women have boys like you to toy with. Submissive men, tiny losers, perverts who get off on being used and humiliated. You're desperate to be used like that, but try not to show it. She tells you she wants to see you wank your little pee-pee, she doesn't believe it actually can. At first you want to, then you realise she has something else in store. You have to cum on your face. She laughs at you for being a cum covered slutty pervert. Just like you always dreamed of.