My newly 3 year old learned to pee in the potty. Sometimes I have to ask him, sometimes he tells me when he needs to go. I still have him diapers because he hasn't wanted to poop in the potty yet and I'm not about to clean up that mess. When do you think I should put him in plain underwear? (Btw feeling the pee and poop on his butt doesn't bother him at all. So I was thinking might as well keep the diaper on for an easier clean-up.) He doesn't have an exact schedule of when he poops.