How is it that the "Kiss of Death" - such a brutal and final gesture - should be immortalised throughout art and literature as a semi-erotic gesture?
Within the mafia, it is, quite literally, a kiss signifying that you are marked.
Death is sometimes imagined to be a "woman in white" who leads you, willingly, into the eternal abyss.
Sometimes, the phrase is used colloquially to be that moment when the woman (or, man) of your dreams tells you that they, "Just want to be friends".
Is a life relinquished, as Shakespeare said, a "Tale told by an idiot; full of sound and fury, signifying nothing"? Or, is it with a whimper and a slump of submission?
In any event, it's that moment when you realise that it's finally over and - for reasons, perhaps, beyond your control, or beyond your repair - you cross over the line like a somnambulist, accepting of your fate.