Mutual self pleasuring.
It wasn't until I was married that I starting taking care of myself regularly..because my ex wife was a freak about it, which I found out about it some 10 or so years into our marriage..she started telling me all about her self pleasuring while we had sex..it turned me on to hear about all her places and methods while I'd grind my member slowly in circles. She also was the type of girl that got your knees wet during sex...
Anyhow, as the years went on our marriage wasn't doing well and I started going out to the clubs alone..I developed a taste for the sex drugs and would always have some on the weekends...I made pretty good money at my job so I'd always bring enough to share with the girls if they wanted some..well this is how it all started, when I'd take a girl out to party I'd always mention how horny the stuff made me and I started asking them if they ever tried mutual masturbation? Some where honest while others acted like they didn't know what it meant..anyhow this went on for like 4 years and believe it or not I've had the pleasure of sharing this activity with 72 other females...only 1 out of 72 said no, and it was because she had an embarrassing method of pleasing herself. She showed me after I went ahead without her..she'd lie on her stomach and grind her clit on her fist.. it wasn't until she watch me that she got so hot she had finish.
So the moral of the story is every does it and it's a lot easier to do it with others with certain party favors. Funny thing is, now I can't even remember their names but I do remember the acts.
Hold my hand to the sky 100% true story.