I often find that the less explaining you do in life, the better things go. I assert my position and if people don't agree, shrug and move on. That'll get em thinking more than explaining does. Explaining sounds like making excuses more often than not.
Also usually, when it comes to matters of this nature, people just aren't gonna get it unless they're trying. So, unless you really need them to get it, say "I'm a guy". If they contradict you, look at 'em like they're crazy, shrug, and leave it at that.
Dennis