Yes, a good number of times when I was in my first marriage (open / swinging) and lost my virginity in MFF.
HYE had an affair?
No, while I enjoy a wide variety of sex I've always been more private about my activities even when I was an active swinger / open marriage (though certainly more public then than now). Plus I wouldn't want to turn sex into work. I'd rather just focus on the pleasure not a camera.
HYE flashed a stranger?
Yes. Despite my current wife not being very much into sex these days, early in our relationship she gave me a blowjob to completion while I was on the phone with my Mom. Was a fun conversation. LOL
HYE secretly had sex in the car during the drive while other driver / passengers didn't know?
Yes. We were driving back to my apartment in Boston - my sister was driving. I gave my boyfriend a bj to completion in the back seat as we drove along Rt 6 on Cape Cod. I used the "slow and quiet" suck and swallow technique, and my bf was very good at not moaning. It was great fun. Repeated a few times in other cars with other people driving, and did get caught once! lol
HYE accidentally sent the "wrong kind" of picture of yourself to a friend or relative?