That is hilarious.
One wears a bra and one doesn’t ?
One can grow a beard and one can’t ?
One has periods and one definitely doesn’t?
LOne grew big with child and appeared to feed them from their front chest appendages and one didn’t ?
One uses a urinal and one doesn’t ? I mean I’ve never been in the urinals with my dad but I’d be surprised if he was queuing for the gents and then once there heading for a cubicle to wee because he actually doesn’t have a penis 
I mean it’s true I have made some assumptions but I’m also pretty sure that my dad has a penis tho I’ve never seen it.