But few swingers, he said, spend an entire evening in the thick of the action. “You need a break – food, drink, a piss, even just a rest – so you go off into the social rooms again. And that’s the second way of meeting people you play with. You’re there, naked or just dressed in underwear or something, and you meet some people and like them, and one of you will say, ‘Shall we go and play?’ so you all pile back in together and the whole thing starts all over again.

“Of course, it may be that, once on the mattress, you have no interest in anyone else playing around you. That’s cool, too,” Paul  shrugged, “you just play with one another. Other people come along; you just shake your head, say ‘No, thanks.’”

Some couples, he told me – again as at drinks parties - attend as couples and will not be separated. Others will stay together for the first hour or so, then, once comfortably engaged, split up, each to pursue his or her own agenda, returning from time to time to check on his or her partner’s wellbeing.

I considered this, and shocked Paul, I think, by telling him, “I think I prefer the ‘go your own way’ policy. I mean, what’s the point of going to a party if you’re going to stick together all the time?”

He said, “Yeah, but… Yeah, OK, I see your point, but it’s your first time…”

“Yes, I’d like you to keep an eye out for me,” I admitted, “but I’m sure I’ll be OK…”