I have a friend who is a swinger and she took me a few times.
I went and watched a few times but never got involved. It's weird to sit next to two couple going down on each other's significant others and just hanging out on the couch watching, then they switch up and it's pretty exciting at first but then kind of like..... jeeeeeeeezus wtf is going on. Like hundreds of people in the club but if you get into the "upstairs" section that's where it was all off the hook.
One guy did ask me to do his wife, but that was a little too much for me. Ya can't go down that slippery slope.