I have always used my sense of smell to screen potential mates. I once met a very cool, cute, smart, funny, skinny supernerd and was very hot for him for weeks...until I got close enough to smell him. I wasn't at all interested in him after that. It was like flipping a light switch.
On the other hand, at that same moment in history, I was with a guy who smelled fantastic to me as long as he didn't get too whiff and skip a bath for a few days. It wasn't the healthiest relationship (we had lots in common, but he was a manipulative drama queen), but it suited me at the time.
Women have never smelled good to me. If I could smell them, the closest they ever got was "neutral, not overtly offensive." But after years of trying to be bisexual, I stopped trying and didn't spend much time with women anymore.
Fast forward. Eighteen months on T. I'm gay as a goose and avoid women like the plague. I have no idea how my nose reacts to them now, but I don't plan to get close enough to find out. But men...WTF, I actually smell men MORE.
And not in a good way. The general rule seems to be that if I can smell him, he smells bad. Not neutral, and VERY rarely good. Going to my gay men's discussion group--we often have thirty-five or forty men in the room--is wonderful, but I frequently find myself wanting to sit farther and farther away from the guys on either side. Going to a crowded movie theater is torture; I've actually lost track of a movie at times because I was overwhelmed by the smell. I've never had that problem before. I mean, I have always had a keen nose, have never liked crowds, and have always sought out less crowded theaters, but now it's a matter of necessity.
I have a theory that gay men are able to be so sexually prolific because they don't tend to have this biological screening mechanism. It makes sense. And, based on trans man autobiographies I've read and guys I've talked to, I thought my nose would become less choosy, not more.
But...men stink. Sigh.