wet blanket
US /wɛt ˈblæŋkɪt/
UK /wɛt ˈblæŋkɪt/

1.
掃興的人, 潑冷水的人
a person who spoils other people's fun by being negative and unenthusiastic
:
•
Don't invite John to the party; he's such a wet blanket.
別邀請約翰參加派對;他真是個掃興的人。
•
She's always being a wet blanket, complaining about everything.
她總是掃興,抱怨一切。