For checking the transcript: https://www.buzzsprout.com/2379282

is someone who spoils the fun by being negative, overly serious, or uninterested. It’s often used to describe people who bring down the mood in social situations.

Examples:

1- We were all excited about karaoke night, but John was such a wet blanket, saying how embarrassing it was to sing in public.

2- During our brainstorming session, Sarah kept pointing out all the problems with our ideas. I don’t want to say she’s a wet blanket, but she wasn’t exactly helping the creative vibe.