Motherbotherer 

A person who bothers their mother with it whenever someone upsets them. Often a weedy kid in school, generally can't take jokes or banter, and still relies on their parents to fight their battles at an age where they really shouldn't.

"That kid went and snitched on us for calling him fat! He's such a motherbotherer."

"What sort of motherbotherer goes to the police over a little scrap like that?"

Motherbotherer by Mickulty February 3, 2013