I've decided I'm not going to discuss my particular genital configuration with people unless it somehow becomes directly relevant to our interactions, like if we're about to have sex.
"Before we get naked, you should know that I have boy parts down there in case that's relevant to your particular sexual preferences."
I believe this is referred to as being "stealth". I realize that implies that I'm being sneaky and deceptive, but it's what suits my lifestyle best so I hope I have your support.