by leaving his mom means deserting her, never speaking her, not supporting her (emotionally and financially), then hes a prick.
But by leaving his mother, meaning that he moves out of the home after marriage, but at the same time tending to his mother’s needs (not necessarily demands and wants), then is he more of a man than the one that brings his new wife to his mother’s home (yes, its will always be his mother’s home) and allows them to bicker endlessly (if they do) for the rest of their lives.