Maadult - An adult who's so mature, they can make a baby throw a tantr

An adult who's so mature, they can make a baby throw a tantrum

My uncle is a maadult. He called my baby cousin a 'mini-me loser.'

My neighbor is a maadult. He took my baby's toy and threw it in the pool.

My friend's dad is a maadult. He told the baby he was a 'disgrace to the family.'