kill-joy

[ kil-joi ]

/ ˈkɪlˌdʒɔɪ /

a person who spoils the joy or pleasure of others; spoilsport.

Origin of kill-joy

First recorded in 1770–80

Not to be a killjoy fact-checker, but this does seem like an important detail to get right.

Jesus Christ, Baby Daddy? |Candida Moss |November 12, 2014 |DAILY BEAST
Some of you do not like to be reminded of it, and think it a killjoy.

Expositions of Holy Scripture |Alexander Maclaren
However, I did my utmost to bear a cheerful and contented mien, for killjoy is but a poor friend.

The Admirable Lady Biddy Fane |Frank Barrett
I dont want to be shown up as a fraid cat and a killjoy, cried Jessie.

The Campfire Girls on Station Island |Margaret Penrose

I did not wish to be a killjoy and a marplot, or I would have forbidden Fred to touch a foot-ball after he entered college.

The Opinions of a Philosopher |Robert Grant
Allan, I don't want to be a killjoy, but you asked for my advice.

The Black Fawn |James Arthur Kjelgaard

killjoy

/ (ˈkɪlˌdʒɔɪ) /

a person who spoils other people's pleasure