It seems to me that if you have kids and are trans, you have to be pretty flexible with regard to "Mom" and "Dad" labels. I know a guy whose kid (now over twenty) calls him "Mom," even in public. It doesn't bother him at all.
So...if you have kids, what did they call you before and after you came out/transitioned/whatevered? Was the label your choice, theirs, or a mutual decision? How does it make you feel, especially if you're out in public (whether the label fits your presentation or not)?
Yeah, I'm childless, but I've always secretly wanted a kid who would call me "Dad." Except I would have to have a child around, and that's not going to happen!