kiss of death
Definition from Wiktionary, the free dictionary
Biblical: Judas betraying Jesus with a kiss.
- A kiss on the cheek that signifies the death of the receiver, as delivered by a mob boss or one with such influence.
- (informal, idiomatic) Something that may seem good and favourable but that actually brings ruin to hopes, plans, etc.
- The role in the soap opera was the kiss of death for Ann's career as a theatrical actress.