After finding your sister’s panties in your bedroom, I decided to stake out your room and my suspicions were confirmed: you’re fucking your sister. But before I can make up my mind of what to do on the subject, I have a few tests to perform. I take out my notebook and proceed to measure how you respond to various visual sexual stimuli. Can you maintain eye contact while Mommy strokes her nipples? What happens if I strip down to my lingerie? Will you get hard? I conclude that it isn’t, in fact, your fault. You clearly have an overactive libido and, as your Mother, I really should be the one to deal with it. So, bring your erection over here and slip it into Mommy. I try not to enjoy it, but it isn’t long before I’m cumming all over your cock—just like your wanton slut of a sister did!