I've no idea; a lot. I grew up in boarding schools, where playing with myself and each other was my favorite group activity. As a young man I frequented Gay beaches and bathhouses, and hung out with various and sundry hippies, Pagans, and other open-minded free spirits who enjoyed nudity and sensuality, and weren't averse to a hard cock. We spent a lot of time in pools, hot tubs, and saunas, and I'd occasionally attend sex parties and circle jerks; some mixed, some male, I've seen and been seen a bunch of times.
In person? Not many. 2 or 3 while jerking together. (Only done this with 1 other at a time, never had the opportunity to do it in a group.) Does online count? If it does, then I have no idea how many people have watched on the occasional cam jerk.
Before I got married 37+ years ago? About half dozen (male and female). Since my marriage, only one. My wife.
Before I got married 37+ years ago? About half dozen (male and female). Since my marriage, only one. My wife.
Well, this would involve doing math and I don't like math. Let's just say more than a few people. Matter of fact I masturbated in front of someone this morning.