I was wondering how the following terms differ semantically? Are they quite interchangeable (in AE)? If no, them please let me know what is the difference between them:
Killjoy: One who spoils the enthusiasm or fun of others.
Party pooper: someone who spoils other people’s fun.
Wet blanket: Someone who ruins other people's fun.
Also, I think they are all in common use in everyday American English. If they aren't, then please define the uncommon ones.