self-righteous

self-righteous
ˌself-ˈrighteous adjective
proudly sure that your beliefs, attitudes, and morals are good and right, in a way that annoys other people – used to show disapproval
   SYN  sanctimonious:
    She’s a vegetarian, but she’s not at all self-righteous about it.
—self-righteously adverb
—self-righteousness noun [uncountable]