My DS is 2.5.
He's been potty trained for about 2 months now.
He only wears a pull up at night. This usually has a good few wees in in the morning.
However, I've noticed that in the day if he naps - even if he naps for about 3 hours - he won't wet himself when he's in underwear.
I'm not sure if it's just because he subconsciously knows that he's in underwear and can feel the difference between a nappy? I'm not sure but either way he never wets through when he's asleep.
When should I brave it and leave the nappy off at night?