I recently joined a gym near my work. Since I work out and exercise before work, I shower and dress for work at the gym. The shower is a communal one so there isn't an opportunity to jerk off in the showers, but there are plenty of other cocks to look at.
The locker room area has a small steam room which has plenty of privacy since the steam blocks the view of anyone passing the steam room's glass door. Last week when I entered the steam room there was one other guy there. We were both naked, I laid out my small workout towel on the seat so I could sit on it and draped my big shower towel around my neck. The other guy was also sitting on a towel but did not have anything else to cover himself.
After a few minutes I noticed him run his hand up his thigh and across his cock and balls, he did this twice. I took this as a sign, so I did the same thing with my right hand. Apparently I read his sign correctly because the other guy immediately grabbed his cock and started rubbing it. Then I slid over to be closer to him and started playing with my cock.
In no time both of us were hard and were stroking. My cock is only about 5', with shaved balls and a small patch of horizontal pubic hair about 1' by 3'. The other guy had a much bigger cock, at least 7' and much thicker than mine, and he was completely shaved which made it look even larger. Neither of us said anything, we just stroked while looking at each others cocks being stroked. After about a minute of stroking like that the other guy reached over and placed his hand on my balls; I immediately removed my hand from my cock and he slid his hand up from my balls to my cock and stared stroking me. It felt so good to be stroked and there was extra excitement knowing someone could walk in on us. Then I reached over and grabbed his cock and started playing with it. Neither of us said a word, we just kept stroking each other. After a few minutes the other guy said he was going to cum and said 'go faster'. I squeezed his cock tighter and stroked it faster. Then he shot 3 ropes of cum up into the air while moaning quietly. While he was cumming his hand came off my cock, but after a few second he grabbed me and stroked me again. Seeing him cum caused was so exciting that as soon as he started stroking me again I was ready to cum myself. I started shooting straight up in the air. Neither of us said a word. After a few second I got up, wiped the my cum up with my small towel and headed to the shower. I hope this becomes a regular thing.