Diaper Punishment Cruel Prolongation

Once he's diapers make him drink at least a liter of water and hold it for at least 5 hours as test to see if he can "hold it".

Make it impossible for him to “hold it” if you want to keep him in diapers and tease him with a clear message that he’s not ready to be out of diapers.   When you go to change him, tease and humiliate him that he’s just like a baby, with absolutely no control.

You can also do this if he challenges you and you want to keep him babies for a long period of time (for example, a whole weekend).