when single I explored this,, met a couple in a pub where the husband was sub and wife was Dom. She wanted her husband to submit to a bloke,, he didnt want to. We started off in the pub her feeding him viagra and then he came home with me. The plan was for me to restrain the husband and bring him off- for him it was the ultimate in submission as another guy shouldnt make him cum. I had to take pics for his wife. It was great fun to be honest. Would love to do something like that again.
I met my friends wifes husband and we used to get together and watch porn/beat off together. This went on for 10 yrs the furthest we got was sucking each other,, was enough for me- never wanted anal. But loved a blokes hand around my cock- at least he knew the pressure needed to make me cum lol.