Seeing him jack off was really hot.
One day I decided to visit my father-n-law. I drove to his house to ask him a question about some yard work I had been planning. When I arrived at his house, the door was unlocked so I went in unaware of what was happening inside. When I walked inside, I saw my father-n-law (Robert or Bob for short) sitting in his recliner masturbating. His pants were around his ankles and he was working his cock very quickly. He couldn't see me because his chair was facing the porn he was watching on the television. I watched as my own cock grew. Seeing him masturbate while watching porn got me really hot. I didn't approach him, I just watched. It was great to see another man masturbate. Growing up in a very strict religious household, I was always taught by my father that masturbation was evil and corrupt. Seeing an adult I respect masturbating made me feel so much better about my own masturbation. I went home quietly and went straight to the bathroom. I had felt my hard cock in my pants as I drove all the way across town.
When I arrived home, I had one of the most explosive orgasms I had ever experienced. I went into the bathroom, locked the door (my wife was cleaning the house at the time) and dropped my pants. I grasped my cock in my hand and within only a few strokes filled my hand with so much cum it hit the floor, wall, toilet, and sink. I had never came so much as when I was thinking about seeing my father-n-law masturbating.