OMG, I knew this MV would be funny, but it was Hilarious!!

U-Kiss & Kim Heechul!

+ a handful of other Korean Celebs.

It's been a while since a MV made me laugh so much!

Before you're all like, "I've heard this song before. I think?"

This is Lim Chang Jung's "The Open Door"

which, is his version of the same song WonderBoyz did for their debut

I wonder how Heenim turned up in the video?

lol

The sad song Heechul instagramed him singing and listening to is also by Lim Chang Jung.

It's called "A Guy Like Me"