My son spies on me having sex (voyeur style), it ends with me not orgasming and being very disappointed, but the guy just leaves anyway. I lay on my bed, to get some rest, then I feel a cock filling me up from behind, it feels really good! I assume its my BF who changed his mind, but its not, its my son! He fucks me for a while and I talk about how good it feels and how much better it now feels. I have a HUGE orgasm, I turn over to thank him but I am mortified to find out it was my son! No one can find out about this, his cock is still rock hard and he wants to fuck me some more. I tell him he must pull out to cum though, we fuck in missionary talking about how wrong it is but it feels so good. I orgasm again, and I feel him cum inside of me too. I am upset but can't deny how good it felt.