Wet dream?

Maybe they won't. Not all boys get them.

Your body might release small amounts of semen you don't notice when you pee or semen is just absorbed by your body.

 

It's better that you don't have, the semen contains many proteins and that's the reason because others boys feels bad even without pmo.

 

Some do experience them while other do not. It does not make a difference whether you have them or not. It is better if you do not because well at first you feel bad and then you have to clean yourself up afterwards which is not so easy (mostly because you were sleeping peacefully and now you have to get up and clean up)