goody two shoes
US /ˈɡʊd.i ˈtuː ˌʃuːz/
UK /ˈɡʊd.i ˈtuː ˌʃuːz/
1.
a person who is excessively virtuous, obedient, and well-behaved, often to the point of being annoying or smug
:
•
She's such a goody two shoes, always following the rules and never having any fun.
•
He was teased for being a goody two shoes because he always finished his homework on time.