My wife and I have been swinging for a little over a year and we both agree that the last thing we want to see/be part of is two guys. This isn't homophobia or whatever, but when I see 2 guys going at it I feel there is something fundementaly WRONG with it.
Now this doesn't mean I'm 'homophobic' or whatever 'anti-gay' name you can give me, but its about the most unsexy thing I can think of short of copraphillia. With couples we've met we've found this to always be the same. I've noticed that a lot of bi-couples get upset that the majority of the swingers community frowns on bi-men (not totaly unlike the same way straight females sometimes feel), but swinging is about what you want to do/see/experiance and a LOT of us males in it do NOT want to be part of that as its totaly unappealing.