Open marriages are becoming more common. CNN recently did a series of articles about this social trend. I can't answer to how "normal" (whatever that means) it is to want to be with someone who is in an open marriage, but I'm that way. I would love to be with a woman in an open marriage. For me, part of it is the kinkiness of it and part of it is the desire to avoid commitment. I'm also just out of a divorce. I just don't want to go down the marriage path any time soon.

Sex is so complicated that it's hard to tell what parts of our sexuality stem from something unhealthy, but it's hard for me to believe that just because you have this preference that it's a sign of some problem.