From Longman Dictionary of Contemporary Englishthe kiss of deaththe kiss of deathinformalSPOIL something that spoils or ruins a plan, activity etc → kiss
Examples from the Corpus
the kiss of death• But its demise was further justification to the movie industry that musicals are the kiss of death.• An "X" rating can be the kiss of death at the box office for a big-budget movie.• Why should living together, in particular, be the kiss of death to hopeful marrieds?• That's got to be the kiss of death.• Although it was very tempting, accepting it would be the kiss of death for the concept.• Yet the onset of daylight, with its much better conditions, brought the kiss of death. 