Swing when you're minging

Just heard some rather disturbing news from a friend of mine about a mutual aquaintance. Apparently he hosts a swingers email list. Not in itself a bad thing - I'm a very open minded kind of person. Its just that he and particularly his girlfriend aren't exactly supermodel types if you know what I mean. It prompted me to ask, "Why are swingers always mingers?" which sounds like a cue for a song, I know. In fact right now I have an image of Rex Harrison singing such a ditty. Probably due to the fact that we've just been rehearsing our show in which I sing 'Wouldn't it be Loverly' from My Fair Lady.