She's Beautiful, But I Shouldn't Want Her.

A few weeks ago I caught my mother cheating on my dad.
I'd left college early and walked into our house to hear my mother making all kind of moaning sounds. Then I heard her say "Yes, yes fuck me there".

I moved to the lounge door, pushed it open a bit and was able to see my mother knelt up on the rug naked. Behind her was a young naked guy I didn't know and even from where I was, I could see him fucking my mums arsehole.

She was loving every thrust and constantly telling the younger man to fuck her arsehole harder.
I know it shouldn't have, but I became turned on and got an erection.

I watched for about two or three minutes before they changed position. My mother mounted the guys large penis and that's when I moved away because she could have seen me facing my direction.
I've not said anything to my dad or mum, however I did masturbate that night in my bedroom remembering what I'd seen earlier.

I know the young guy has been round to our house again since, and I've just found out my mother has had other younger lovers.
What's strange, is I now think my dad knows she's being fucked by young guys. The other strange thing is, I cannot stop getting boners around my mother, and she's definitely seen me horny a couple of times.

Only last week when she was stood in our kitchen wearing just flimsy almost see through knickers and a short t shirt, clearly showing her hard nipples, I got a hard on in my shorts and my mum said "Maybe you should go and sort that out" pointing at my cock bulge.

As I walked away, she added quietly (but I heard it) "Tempting".
My mother is very attractive, and I shouldn't be having the thoughts I am about fucking her, but I am.