Don't be such a party pooper, let's have some fun!
buzzkill
Frequency:
70
%
His negative attitude was a real buzzkill at the concert.
spoilsport
Frequency:
60
%
She refused to join in the game, calling her a spoilsport.
wet blanket
Frequency:
50
%
His constant complaints put a damper on the evening, like a wet blanket.
Idiomatic Expressions for killjoy
Phrase: Killjoy alert
Meaning: A warning that someone is about to spoil the fun or excitement.
Usage: When he started criticizing the party decorations, we all exchanged glances and said 'killjoy alert.'