No need for a restroom

This little dude will pee anywhere--Taco Bueno parking lot, Behind Walmart, on the side of the highway and of course off the back porch. He has a smaller bladder than I do so unfortunately he has peed in all of those places. Bueno and Walmart have happened when it's just been me with all 3 kids. He always waits until we're all loaded in the car and then says he has to go. Instead of unloading all 3 kids again I've just had him go outside.

His Daddy taught him to go off the porch and that's what's started it all.