K is usually used for replying to a text. (read definitions) The only reason people reply saying this, is because they are bitchy, and just plain-out annoying. Don’t reply to texts saying “k”!
Basically if you end a noun with K immediatelyafter whiletalking to someone you’re basically calling said noun “lame” or “dayroom” the usage is really difficult considering that “K” originates from New York
“Bro this weed Keegan served me is Reggie...” “ Keegan K why u copping from him in the first place”