Mr. Poolcheck calls the pool “she”, Mermando does too. Poolcheck not only knows about Mermando, Mr, Poolcheck also spends quality time with him. Mermando, unfamiliar with human customs, picks this up. Noone else does because Poolcheck never does smalltalk with pedestrians. And he´s regarded as super weird.
Who else speaks with this “weirdo” and calls a pool a “she”. No one.