Bl manga where one of the mc is a child assassin and he joined Royal's family recruitment ...

Bl manga where one of the mc is a child assassin and he joined Royal's family recruitment for servants, and he was assigned to an unwanted young prince? (Not so sure).. and during the assassination of the royal family the child assassin helped the young prince, by giving him his clothes and mask so that he can escape, but they failed cause their cover was blown by one of the Assassin family's member. That's when the Child assassin's mom showed up. Thanks in advance (*˘︶˘*).｡.:*♡