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Demi Lovato is blasting Lady Gaga for her performance at the South by Southwest music festival last week. 

Demi has taken to Twitter to criticize Gaga for "glamorizing" eating disorders, after Mother Monster had a friend vomit on her body as part of an onstage stunt.  Lovato called Gaga's antics "sad" and said in her opinion, there was nothing "cool" or "artsy" about her actions. 

The former Disney star, who battled with eating disorders herself before seeking treatment in 2010, argued that "putting the word 'art' in it isn't a free card to do whatever you want without consequences." 

Demi added that she is "still a little monster," but as an "activist" she felt something had to be said. See her tweets below.