mama's boymama’s boy /ˈmɑːməz ˌbɔɪ/ noun [countable] American English 
a boy or man who lets his mother look after him and protect him too much, so that people think he is weak SYN mummy’s boy British English: 
You’ve got to stand up for yourself – stop being such a mama’s boy.
a boy or man who lets his mother look after him and protect him too much, so that people think he is weak SYN mummy’s boy British English: You’ve got to stand up for yourself – stop being such a mama’s boy.