goody two shoes

US /ˈɡʊd.i ˈtuː ˌʃuːz/
UK /ˈɡʊd.i ˈtuː ˌʃuːz/
"goody two shoes" picture
1.

sainte nitouche, enfant modèle

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.
C'est une vraie sainte nitouche, elle suit toujours les règles et ne s'amuse jamais.
He was teased for being a goody two shoes because he always finished his homework on time.
On se moquait de lui parce qu'il était une sainte nitouche, car il finissait toujours ses devoirs à temps.