Step-Sister Needs Help With Math

Oh my gosh, I'm having so much trouble with my math homework! What am I going to do? It's due this Friday! I can't believe I'm this bad at math... Hey, you're amazing at math, aren't you! I always hear from my math teacher how good you were in her class. Would you consider helping me, please? I really need help with this, I have to admit it... Oh, please, would you? Wait, what!? You want me to have sex with you in return? Uhhh, I don't think... just because it happened once before, doesn't mean... I... okay, well, look we can't be caught okay? Make sure no one's home. Absolutely no one can know. We can't be careless doing something like this. I'll give you a handjob, and maybe... oh god, let's just fuck! I can't stand it any more. I'm horny and I really need your help. Fuck me, Big Step-Brother!