Great reading on this thread - here are my contributions:
In 1979, I was 25 and dating a guy who was 38, divorced, dad of four. He brought me to the Mine Shaft, a now closed sex club in Manhattan. I felt like Alice in Wonderland....sex everywhere. My bf took his cock out and started stroking it, and I went down on him. Another guy was getting fisted in a sling. Cocksucking and fucking everywhere. I went up to the bar to get us drinks, and was felt up and down, groped and played with. The capper was one of those *shudder* moments. I had to pee, and asked him where the men's room was. He directed me to this large room that had bathtubs in it, and there were naked men in the tubs, sucking off others. He told me, just go there, unzip and start peeing.... so I did that, and a mouth clamped immediately onto my cock as I peed. It was an unforgettable night.
The following year, I had an MMF threesome with 2 friends... the guy was 'straight' and very hung.... we were all over each other - I blew him while she blew me; he sucked me while he was fucking her, etc. We are all 25 or so, and it happened in his parents' home - they were away on vacation.
More recently, I had several hot experiences with an older guy (60s to my early 50s), groping each other on the bus on the way home in the dark.... and one occasion, I went down on him - we were in the back seat. He was also married, which turned me on.
Slutty? yes, but great fun.....