As I've discussed the "alternate" pants that Middle Son has been wearing lately, I've had a couple of people suggest that I try putting him in a kilt. Which is sort of an interesting idea. If he could be convinced to wear underwear under it and keep it on, it would be a possibility.
MomC got some UnderArmor boxer-briefs for him. She says that he seems to like them, but he wants to wear them as pants, not underwear. Which doesn't really fly out in the world. But if he'd wear them under a kilt...that might work.
I think I'm going to have to give the idea serious consideration.