I found my panties underneath your mattress, and some of them I know I had worn after I had sex with your father. So, this is what you do? You like to sniff my cum stained panties after I've had sex with your father and jack off? Well, it's not totally abnormal for a boy, but there does have to be a punishment.
You see, your father is cheating on me anyway, so this is how I'm going to get back at him. You're going to fuck me. If you don't, well then I'll tell him what you've done with my panties.
Of course you're going to go along with it because you don't want him to find out, and just as we begin he calls and I answer. Sitting on top of you I tell him I'm reading a book. He's of course "working late" again, and apologizes over and over, and I simply say "it's fine", but in reality I know what's happening, and now I'm getting him back by fucking his son. Oh, and I should mention the one last thing you will be required to do, since you love licking my cum stained panties so much; you're going to cum inside me and then lick it all out. Imagine how good mine and your cum mixed together is going to taste.