Lol is the best response you can come up with? Kids get used to things, especially if the adults around them aren't freaking out about it and the child in question stands up for him or herself. Considering that the kid here has a supportive father I don't think he's just going to crumple up into a ball of depression when other kids make fun of him.
I can speak from experience here, actually. As a stubborn child in kindergarten, I insisted on playing the part of the mother in little games of house. The teacher didn't scold me and when kids told me I was being a girl I said that I thought girls were great so what was the big deal? They got used to it, I got to play the part of the mom, and eventually I got sick of playing house and moved onto other things.
It was no big deal.
I've also spent a great deal of time in kindergarten and first grade classes, as both my mom and grandma taught at that level. I don't think you guys really know what you're talking about, honestly.