Son, I talk to your teacher and she said your grades are slipping. I have an idea for a reward system. Well, I would give you sexual rewards for doing well. I know you're into mommy porn, this would be even better! This would be the real thing! If you do good on the test in two days, I'll give you a blow job. If you do good on the test after that I'll let you fuck my pussy (and cum in it). And son, if you get a good report card, I'll let you fuck my ass (and cum in it)! Does that sound like a good reward plan son?