Potty help!

Ha

My son is 2.5 hes doing SO GOOOD using the potty. He doesnt even say when he has to go, he just does and then washes his hands(we usually sanitize too just in case) BUT he will only do it if he's naked on the bottom. The second we put anything over his bottom, he pees like it's a diaper.

Also hes suddenly gotten into this phase of "I cant mama" "I cant pee" even if hes drank tons of water.

He pees almost excessively some days but will hold it if he just isn't feeling it.