I can buy into the notion theoretically, and I do have a friend who's in a very longstanding group marriage (by which I mean 30+ years)... and I've written one with HH/AK/WB. (Tho I think Edrington would be quite a match for Captain Jack.) Guys seem to like the notion more than women, tho there are a lot of menage stories out there, mostly by women. I see it as kind of like the notion of sex in the woods--sounds very exciting but in reality there'd be lumpy ground, sharp twigs, mosquitoes... some things work best in fantasy.