A mother is the person who bandages your knees and wipes your nose and makes you wear a coat when it's cold outside and cooks your favorite foods when you're sick and loves you even when you've been horrible to her.
You ARE Mo's mother, boomerang. The woman who gave birth to him hasn't done these things. She's not his mother, YOU are. You've earned the title.
Mr. B is waaaaaay off base! And you may tell him I said so.