a goody two shoes
A goody two shoes is someone who thinks they’re better than everyone else because they never get in trouble and act like they’re morally perfect.
My goody two shoes neighbor would never even eat pizza and thinks everyone else is a sinner.
My goody two shoes coworker would never even say a bad word and thinks she’s better than everyone else.
My goody two shoes friend goes to church every Sunday and lectures me about my ‘sinful’ lifestyle.