Demi Lovato posted a disturbing picture on her Twitter page, giving fans a sneak peek at her upcoming cameo on Grey's Anatomy. The star of Disney’s Sonny with a Chance recently revealed she would be heading to Seattle Grace for a cameo on the hit ABC medical drama. OK! VIDEO: DEMI & JOE FINALLY GO PUBLIC WITH THEIR RELATIONSHIP Looks like Demi is branching out from her Disney roots and really diving into this dramatic role! Read More >>