I had (past tense) a friend who had grown up conservative, got a good stable job, married a good stable man with a job and was just starting a family. I hadn’t seen them in two or three years when they came to visit. What a change. Somehow the subject of cheating came up and neither of them saw any problem if the other cheated. That was the last time we saw them.
I’ve known couples like that. The psychology behind it all is amazing (not in a good way). I was invited to a party years back without the heads up of what kind of party it was. It was a swingers party. No one was pushy and there was nothing happening out in the open (unless you walked past a room with the door open). The thing I found most remarkable is I could tell the ones who had been at “that” for a while. The look in their eyes was, well, dead. No soul left. Sure, they were laughing and partying it up, but nothing seemed to satisfy them at that point. Like they burned themselves out sexually.
While I will admit to be intrigued by all of it, that is a dark lonely place those people seem to end up in.