An abbreviation of the word awkward to describe a situation so awkward that simply describing it as "awkward" isn't enough. Hence, the usage of the most awkward word, "awk."
Joe: Oh, are your eyes closed in the picture too? We're matching!
Jim: ...I'm asian. awk.
guy one: did you hear? Steff has an STD!?
guy 2: oh shit, and i was gonna fuck her silly too...
guy 3 walks up: Guys Guess what? I FUCKED STEF LAST NITE!
guys 1 and 2: awk....