Many years ago when my wife and I were in our early thirties and her parents were in their late fifties, we lived about a ten minute drive from their place. One Saturday afternoon we went over to their house for a visit. When we first arrived, her father was not around so she and her mother decided to go shopping. I declined and went down to their basement to watch TV. I was snooping around in the cupboards above the TV and found some skin magazines. They were real hardcore sex books and had me erect in no time. I dropped my pants and shorts and started jacking off. I hadn't been at it long when I sensed I was not alone. I looked back over my shoulder and there stood my father-in-law. I expected to be berated for my actions but he wondered if I wanted a partner. I said I'd be happy to have him join me.
Soon he had his pants and shorts off like me and stood there with the longest, hardest cock I had ever seen. It wasn't really big around but it was long! We decided to sit on the sofa side by side and jack together. Neither of us were circumcised and the purple heads of our cocks were appearing and disappearing in rhythm. He suggested we try to last long enough to cum together. I was ready to explode at any moment and told him so. He said for me to stop and let him catch up. I stopped for a couple of minutes and he signaled his approaching explosion. I started up again and soon was pumping stream after stream of white ropey cum all over his hand and cock. He jerked two more times and popped his cum onto my stomach and chest.
We sat still for a few minutes until the excitement built up once more and started fondling each other to get each other erect again. This time when we were both hard, we jacked each other to a mind blowing second climax. We each took a finger and wiped up some of the other's cum for a taste. His was slightly saltier than mine but not too much so. We cleaned up and agreed it might be fun to do again some time. I'll relate the story of our next get together at some later date.