I ask my DS1 if he needs to go & I get "no mummy I already went to the toilet today at kindy" or "it's empty, my doodle is all empty" LOL. He holds on too, and often has accidents....but it's all learning we just roll with it, nice a casual. He's never had a no2 accident in his pants, will always do that on the toilet and he leaves that til the last minute also. You know he's going as he all of a sudden just runs past me butt naked in one big hurry...soooo funny!!
When we are heading out I just say, "we can't go to XYZ yet until we've done a wee", he always does one then before we go.