That’s partner swapping, or wife swapping in the mid 20th century, which is a subset of swinging. Plenty of swinging is bunches of people in a pile, or mingling and pairing. They’re supposed to be consent and boundary conscious, but are not always (especially when booze or drugs get involved) which is the primary source of sore feelings and getting uninvited to future events.
Black humor doesn’t work when your company figures largely in responsibility for the mess.