a haha funny
You laugh so hard at something that's not funny you start crying. You say 'haha funny' because you're trying to hide the fact that you just got insulted.
@sam: I just got a haircut. It's the best. @you: haha funny
@mia: My dog can talk. @you: haha funny
@joe: I just got a tattoo of a banana. @you: haha funny