Answer: spoilsport

AnswerCrossword Clue
SPOILSPORT

Killjoy

SPOILSPORT

Stick-in-the-mud

SPOILSPORT

Wet blanket

SPOILSPORTWet blanket.
SPOILSPORT
Cousin of a wet blanket.
SPOILSPORT
Kill-joy.
SPOILSPORTPessimist's cousin.
SPOILSPORTWet blanket's cousin.
SPOILSPORTSaboteur on a petty level
SPOILSPORTKill-joy
SPOILSPORTCoddles wine
SPOILSPORTKill-joy runs harbor for ill-gotten gains