Wet dreams, also called nocturnal emissions, can make a boy feel embarrassed. A wet dream occurs when semen comes out of the boy’s penis as the boy is sleeping, possibly because of dreaming about having sex. It can also happen without dreaming about sex. If a boy has a dream, he usually doesn't remember it when he wakes. Wet dreams stop when the boy is a little older. Sometimes, the semen leaves a wet spot on the boy's bed sheets. If the boy wants to, he can talk to a parent or guardian and ask if he can do his own laundry. That way, no one else will see the wet area and know the boy had a wet dream.