Your author was once introduced by two female friends to a young man, around 20 years old, who wanted to play with mutual masturbation while the two young women watched. We took off our clothes, and he jerked me off for a while. Being older and experienced, I was able to enjoy the stroking, but held off cumming just fine. Then, we decided to switch the attention to him. I had him take my place on the bed and I reached out and touched his penis with my forefinger. He ejaculated right then and there. We didn’t happen to get together again, but my guess is that subsequent sessions would have lasted longer. I would have made it a point to introduce him to techniques to prevent accidents, and I think he would have appreciated practicing with me.
In most forms of sexual play men would prefer to delay their ejaculations, to get as much joy out of a situation as possible. Women generally take longer to orgasm than men, so it is also important to many women that men delay, so both can have their orgasms at nearly the same time. Young men have more trouble with premature ejaculation, also known as ‘accidents,’ than older men.