I went to Con.txt, the every-other-year one that's local to me. You would not have been the only guy there, but I'd be lying to say you wouldn't be outnumbered by at least 20:1. And of the guys, I got the impression about half were there because their female partner was. (Oh, the irony in that statement, as you note!) Probably the highest concentration of guys I saw in one place at the con was in the boardgame room that was running opposite the dance party opening night, and by "highest concentration" I mean like three. I did not feel like they were intruding (hey, I like having people to play games with), but I can understand why you might feel that way.