SLOB

Abbreviation for: "Serious Lack Of Banter".

A person, situation, or encounter without banter, i.e. without any jesting or amusing back-and-forth.

"The party was no fun. Such SLOB."

Alice: "I talked to them for a while, but it was quite a drag."
Bob: "Oh, how come?"
Alice: "The SLOB was stunning."