I don't really flirt except when I'm not serious, and I'm definitely not looking for dates or a relationship. Maybe after I get my bottom half taken care of.
I've attracted the attentions of a couple of creepy guys and a nice guy about twenty years older than I. I flirted with a guy I was working with at Pride a few years ago, but I had no intention of going anywhere with it.
I thought I looked pretty female for quite some time after I started being read consistently as male, and I know that a lot of other guys have had the same experience. I don't think we can trust our own perceptions on that count, at least not 100%.