The first time I had another man's balls up on my face was a few years back.
My wife and I met with couple we met online, and agreed to meet up with them. We decided to treat them out to dinner first, and then head over to a hotel. We'll just call them Mr.Davis and Mrs.Davis. They were both in their early 40s when we first met them.
After we finished dinner and headed over to the hotel, all four of us made ourselves at home, and popped open a few drinks. After about a few minutes of drinking and more chatting, we finally got more physical. I helped Mrs.Davis get out of her clothes, and she helped me get out of mine. My wife helps strip Mr.Davis, and he helped her get nude. From there, Mrs.Davis and I started kissing, hugging, caressing each other, and complimenting each other, while my wife and Mr.Davis did the same thing to each other. Of course the fun part, I was having sex with Mrs.Davis, and my wife was having sex with Mr.Davis.
Now after about 20 minutes into having sex with the Davis couple, my wife and I got into 69 position. My wife began sucking my cock, and I of course was eating her pussy. Mrs.Davis decided to help suck my cock as well, sharing it with my wife, and I enjoyed it a lot. As for Mr.Davis, he went behind my wife, and started fucking my wife in doggystyle position. The thing was, Mr.Davis' balls hung low, so every time he thrusted, his balls would swing back and forth. At one point, his balls started rubbing my face, while I was eating my wife's pussy. His balls were pretty sweaty too, or at least I think they were, but it could have been my wife's juices. I couldn't help it, but decided to give Mr.Davis' balls sniff, which didn't smell bad. I also did give his balls a couple of licks, which I would describe the taste as meaty.
In the end, all four of us had a lot of fun, bringing out orgasm after orgasm, and cumming a lot. It's a shame they decided to stop swinging, but we had fun with them while it lasted.