I didn’t hear my son go into the bathroom before me, so when I walked in, I was surprised to see him sitting on the toilet seat with his underpants around his ankles, legs spread wide, and jerking off his very hard and huge cock. I had never seen him with an erection and certainly never while he was in the throws of an orgasm.

His hips were pumping his fat cock into his fist, which was sliding up and down his pre-cum slimy cock. I had not seen so much pre-cum oozing out of a cock except out of my own when I was really hot to cum. The muscles in his legs were flexing, so I knew he was going to cum any second, and I suddenly felt embarrassed for him in his private moment, but I couldn’t tear myself away for some reason.

He couldn’t see me right away, because the door into the bathroom is behind the toilet, so I was still a little behind him. I could see his cock head begin to flare wide and his piss slit started to open and shut while he stroked himself with long smooth strokes.

He sure looked like he had done a lot of this, because he made it look really hot. The pre-cum was now flowing steadily out of his cock and flowed down over his pumping hand. His cock was all greased up from the stuff, and I could actually hear the sticky sounds of his jacking off.

I realized my cock was getting hard, and it shocked me. I had never seen another guy jerk off, and here was my own son about ready to explode cum juice all over the place. I rubbed my dick through my underwear, and it got instantly hard, tenting out my underwear.

I watched as my son’s legs now lifted off the floor and he spread his legs really wide and pushed his hips up into his fist. I started rubbing my hard-on along with his strokes, knowing that I really wanted to pull down my pants and stroke my cock to an orgasm with him.

Then I looked to my right and caught his reflection in the mirror. He was looking right at me! Shit, I was caught, and I didn’t know what to do. I froze looking at him and his cock, which now began erupting, and he started moaning with each pump of his cock.

The cum sprayed right past his face and hit the wall behind him, and then two huge globs of creamy cum hit him in the face and mouth, and he licked it off his lips and swallowed it! Six more jets of white cum hit his chest, and he squeezed out a huge glob of cum while he lowered his legs down to the floor.

I quickly backed out of the bathroom while he wasn’t watching me and ran to my bedroom. When I got there, my underpants were wet with my own pre-cum, and I sat on the edge of my bed remembering what I had just seen. My cock was pulsing with blood, and I wanted to jerk off so badly, but I was really worried about what my son was thinking of me watching him jerk off while I was rubbing my own cock. He seemed more excited when I started rubbing my cock, and that’s when he came all over the place. Did he enjoy somebody watching him jerk off? Did he want me to see him? Did he plan the whole thing?

My mind was going a mile a minute and I didn’t hear my bedroom door open. Then my son came walking in.

“Dad, are you alright? I hope you aren’t mad at me for what just happened in the bathroom.”

I quickly tried to cover my hard-on with my hands, and I leaned over a little to cover the wet spots all over my underwear.

“No, No. I am sorry, son, for barging in on you like that without knocking. I’ll be more careful from now on.”

I was really nervous thinking about him knowing I had watched him jack off and cum all over himself before I left the bathroom. If he hadn’t caught me watching him in the mirror, I think I would have pulled down my underwear and jacked off with him. I couldn’t believe I was thinking this, but the sight of his hard cock had really made me horny, and the pre-cum that I leaked was more than I had ever leaked before.

“I saw you in the mirror, Dad. At first, I was really scared and embarrassed, but I was so horny that I couldn’t stop jerking off. Then when I saw your cock start to harden and you started rubbing it, I went over the edge and had to have an orgasm right then. It was really intense, knowing you were watching me and getting turned on, too. I have never done anything like that before. Have you?”

“No! Never! I swear it, Rick.” I said to my son.

He was still only wearing his underpants, which were not really covering much of his body, and I could see the damp stains on the front of them. When I looked up at him, I could tell he saw me looking at his crotch, and he gave a little smile and rubbed his stomach just above his crotch.

His muscles were well defined, and his ass looked really tight in those tiny underpants. I couldn’t stop looking at his crotch, and his hands now started to roam lower to the elastic band of his underwear. He slid his fingers in just a little.

“Dad, did you get excited when you were watching me in the bathroom? Your cock started to harden the minute you saw me sitting on the toilet stroking my cock. When I saw you watching me, my legs started to spread open all by themselves like I wanted you to see my whole crotch and balls and horny cock.

“My pre-cum started flowing out the tip of my cock more than ever when I saw you reach down to your underpants and feel your hard cock through the cloth. It looked like it was getting huge in there. It really started to turn me on, and I couldn’t slow myself down.

“Normally I like to stroke for an hour and have a really strong cum, but seeing you stroking your cock while watching me was having a really strange effect on my cock and balls. They felt like they were building up a huge blast of cum, and I knew I wasn’t going to be able to hold off for long. When you finally saw me in the mirror looking at you, I nearly came right then thinking you were going to run out of the bathroom or start yelling at me. But when you kept watching me stroking, I knew I had to have a big cum to show you what I could do.”

While he was reliving this whole event, he was now beginning to stroke his cock through his underpants, and I could see his cock begin to harden. My own cock was still hard from before, and I found myself rubbing it while trying not to be too obvious to my son.