Peeing in the pool

Little Johnny was called over by the lifeguard at the swimming pool.
"You're not allowed to pee in the pool," said the lifeguard. "You're going to have to leave."
"But everyone pees in the pool," protested Johnny.
"Maybe," said the lifeguard.
"You're not allowed to pee in the pool," said the lifeguard. "You're going to have to leave."
"But everyone pees in the pool," protested Johnny.
"Maybe," said the lifeguard.
Spoiler: