Sometimes I play age games in which the adult plays a child of about thirteen years old who wet the bed. That's the reason to punish and treat him as a baby.
Some people need to be punished as well. Standing in a corner, spanking, tying you down and even more extreme punishments are possible, but not necessary if you don't like it.
If you like it it's also possible to play an hour or so in the SM room after the baby game.