Acronym for "don't kill me". Often used when somebody says something that somebody else finds really funny, alluding to them 'dying' of laughter.
Sometimes used sarcastically.
Guy 1: "Dude my mom's so technologically impaired that if you gave her a baseball bat and told her to ruin my computer, she would beat the keyboard to death."
Guy 2: "HAHAHAHA dkm"
Guy 1: "Dude, that new technoeurosailorscenecore band from Woodbridge is the shit! They're such excellent musicians!"
Guy 2: "Yeah o.k. LOL dkm"