My first contribution. English is not my mother tongue, so please be understanding if you don't find the style fluid.
I had experience with a few of my buddies when I was much younger. Mutual masturbation with one buddy, then helping another buddy discover mutual masturbation and oral. After years of inactivity in mutual, I just had an experience a few days ago. I was riding my bike on trails in a nearby park that has a reputation as a cruising area. I thought it would be quiet on this late-Fall afternoon and that I could find a secluded spot where I could at last jerk off and get some relief. I am married, with kids, and having some time and space to myself is next to impossible. I finally found a secluded spot, got off my bike. At the same time, I came face to face with a middle-aged gentleman whom I had seen park his car just as I got in the area maybe 10 minutes earlier. He struck up a conversation with me, small talk about the nice weather (chilly, barely above freezing), then talking about it being a nice horny corner, and then asking me if I was horny. I replied that I was a bit horny. He then moved closer to me, looked at my crotch, then looked around, moved within a few inches of me, then gently grabbed my crotch and started rubbing it. I did the same to him, and when he slid his hand inside the elastic waistband of my pants, I figured I could unzip his pants and start gently rubbing and stroking him. He started complimenting me about my big balls, which he was gently caressing with one hand, while gently and deftly rubbing and stroking my hardening cock, which is average at about 6 1/2' long, but fairly thick. I pulled his zipper down, undid the button on his jeans which he was wearing without a belt, providing almost instant access. I got his cock out, a beautiful circumcised one of a fair size, and started stroking it. I had never played with a cut cock before, so I was not quite sure how to stroke it. I stroked it not too fast, not choking it, gently rubbing the palm of my right hand over the top of it. He got hard pretty quickly. I tried to play with his balls, but they seemd to be hiding somewhere, they were not what you would call 'hangers'. He tried snuggling against me to kiss my neck, but I am not into that stuff, and he did not insist. It did not take me long to feel my ejaculation building up. I warned him twice that I was about to cum, almost expecting to have him start sucking me off, which we both would have enjoyed (me for the sensation, he for the sweet taste of my cum), but he did not relent and kept caressing and stroking my cock and balls, until I shot into his hand. He just kept gently milking my cock until I was through, then shook the cum off his hand. 'You really needed it' was his comment, and I agreed with him on that. He then put my cock and balls back into my pants, and slid them back up. He did not seem to want reciprocation at this point, putting his own cock back into his jeans. He repeated that he would love to play with my big balls again and he could give me his phone number if I wanted, which I did not bother asking. We confirmed that we were both married, and he gently squeezed my ass saying that he liked that too. We parted ways there. A few minutes later, as I was doing the trails, we ran into each other again. He gently squeezed my crotch again, then my ass and just below, telling me that it was very firm and that he just loves that. But I was satisfied, did not feel like exchanging more pleasantries, and rode out of there. Replaying the scene in my head later that afternoon and evening got me so horny again that I had to masturbate twice to completion in those few hours. Not bad for a guy in his late fifties... Please post comment, I might contribute again, this time about my much earlier experiences!