priggish
prig-gish
adjective
Excessively proper, self-righteous, and morally superior, often in an annoying way.
"His priggish attitude annoyed everyone at the party."
Thesaurus
Synonyms: victorian, prim, square-toed, strait-laced, proper, tight-laced, straitlaced, straight-laced, puritanical, straightlaced, prissy, prudish