expression, godan verb (-su)
spoil the mood; ruin the atmosphere
Used when someone's words or actions break a pleasant or harmonious atmosphere.
彼の一言で雰囲気を壊してしまった。
His one remark spoiled the mood.
せっかくの楽しいパーティーなのに、そんな話をして雰
We're having a fun party, so please don't ruin the atmosphere with that kind of talk.