Just Kidding. You fail.
Usually added at the end of a praise to make someone feel even worse when you put them down.
22:43 - Kon: Aren't you happy that I gave you it? :(
22:43 - Krabman: Yes! :D
22:43 - Kon: XD
22:43 - Krabman: Just kidding. You fail.
22:43 - Krabman: Yes! :D
22:43 - Kon: XD
22:43 - Krabman: Just kidding. You fail.