Step-Dad Masturbating

I came home early from school due to illness. I caught my step dad masturbating in his office to porn. He didn’t see me but I watched him. His penis is very fat and almost like he’s holding a Coke can. His pants were to his knees and he came into a washcloth. I’ve never seen in person a man masturbate and now I can’t get his erection or him out of my mind. I’ve masturbated twice with that imagining in my head. So wrong. Funny how something like that changes a person’s thoughts and desires. I shouldn’t be desiring him and won’t act on it but still.