“Playing ‘Bad Romance’ on the piano and pretending to be @LadyGaga,” Williams tweeted before liberating the video. “Why haven’t I ever done this before? Most fun I’ve had in ever.” And, later: “feel a bit crazy posting this… but you asked for it! my apologies to miss gaga. love, your friend, lady haha.”
Watch Hayley’s (er, Lady Haha’s) “Bad Romance” after the jump and see what you think.
(Follow the Music Mix on Twitter: @EWMusicMix.)
More from EW.com’s Music Mix:
Erykah Badu’s naked “Window Seat” video: Watch the provocative clip here
Justin Bieber, Rihanna perform at Kids’ Choice Awards 2010
The awesome Gaga/Beyoncé “Telephone” parody video you knew was coming
Broken Social Scene: Hear two awesome new songs from Forgiveness Rock Record