A to the K
You send this when you're done with someone, or you're so tired of their nonsense that you just want to die.
My girl sent me a 1000-word text about her ex. I replied with a K and went to sleep.
He kept texting me about his dog. I K'd him and never spoke to him again.
I was at work and my dude kept sending me memes. I K'd him and went back to my grind.