spoilsport

a person who spoils the pleasure of others if you don't want to play, at least don't be a spoilsport Synonyms drag, grinch, party pooper, killjoy, wet blanketRelated Words fuddy-duddy, goody-goody, Goody Two-shoes, old maid, stick-in-the-mud; defeatist, Jeremiah, knocker, pessimist; complainer, crab, cynic, grouch, grump, sorehead, sourpuss, whiner; bore, downer, dripNear Antonyms cutup, jester, live wire; carouser, celebrant, celebrator, merrymaker, rejoicer, reveler (or reveller), roisterer; libertine, playboy, playgirl, rake