Like when people say jk, which is internet slang for just kidding, but they actually say the letters. In this form, you elongate the y sound, so you say "jayyy kayyy!". It means you are just kidding, and is much cooler to say out loud than just "jk" or "just kidding!".
Friend 1: "We should get his number... and stalk him."
Guy: "WHAT?!"
Friend 2: "Haha, jayyy kayyy!"
A retard on discord who loves controversial topics and cannot stop getting groomed by the notorious Casper who is in his 20s and is an admin in a shit server. She also has terrible aim in Rainbow Six Siege, she saw the enemy below her but failed to aim down the sight at him and died.