haha j/k! - This is when someone says something dumb just to make you th

This is when someone says something dumb just to make you think they're not a complete idiot.

I’m gonna fail the test, haha j/k! (He failed the test.)

I’m gonna eat your face, haha j/k! (He ate your face.)

I’m gonna beat you up, haha j/k! (He beat you up.)