I've never submitted a story, but this one hopefully will be good..
My son and I have a very close relationship. I've never had any sexual feelings towards him, but as he is 14, I figured he masturbated.
But last week I got 'proof' of it I guess you'd say. I left for work, around 8:30 pm, and when I was halfway there I noticed I forgot my wallet. I decided I could run back home and get there before I was too late, so I turned round and headed back home.
I got the door unlocked, and surprisingly our dogs didn't bark as they usually do. After noticing this I heard moans coming from my son's room. I went to his door, seeing it half open. He was sprawled out on his bed, with some porno on. His penis was probably as big as mine, around 7 inches, and he was working all of it at it's hardest. I didn't even think to bother him, but the whole voyeuristic quality of the situation got me very turned on.
I grabbed my wallet, got back in my car, and started masturbating right away. I came all over my steering wheel and all over the armrest, but thank god not on my pants!! I started the car right back up, still feeling the twinge from cumming in my penis, and headed back to work. My son never found out about this, at least to my knowledge. But I know a few boys are out there reading this now, thinking 'Is it my dad?' Well maybe it is!