I've just gotten out of the shower and am taking my time drying off lost in thought when I hear something. I think that I'm alone in the house. My son isn't home. So I nervously call out "Who's there?". I open the bedroom door wider and see it is my son. At first I'm relieved but then I notice something strange. He is naked and using a pair of my panties to stroke his cock with. I'm shocked and disgusted. I don't suppose I should be so surprised because all the signs were there. My panties kept coming up missing and then reappearing with strange stains on them. And I kept having a feeling of being watched when I thought I was alone. Upon thinking about it I decide maybe if I let him play this out he will stop this behavior. So I invite him in. I take the panties from him and start stroking his cock with them myself. Then I remove my towel and lay back on the bed naked. I fuck him but tell him that he has to let me know when he is going to cum because Mommy is not on birth control. Well, of course he fucks up and fills my pussy full of his cum. I am so mad. (Solo video - sex simulated with dildo)