Demi Lovato criticizes Mariah Carey for 'dissing people'

Demi Lovato has reportedly slammed Mariah Carey for the "nasty" way she treats Jennifer Lopez.

The Heart Attack singer allegedly commented on an Instagram meme comparing Mariah to Ariana Grande, with the caption, “When you order it online vs when it arrives", which hints that Ariana cannot match up to Mariah.

Demi wrote, "You got it the wrong way around honey," hinting that she preferred Ariana to Mariah, and she later explained her remarks by criticizing Mariah for the way she treats people.

“Mariah is a legend and is so talented but constantly disses people," she is reported to have written in an Instagram comment. "It’s nasty the way she treats Jennifer. Ari (Ariana) did nothing wrong.”

Mariah famously told paparazzi, “I don’t know her," when asked about Jennifer in the early 2000s and they have both been asked about it ever since. The Jenny From the Block singer recently told host Wendy Williams, "(Mariah) is forgetful I guess! We've met many times."

In May (16), Mariah told Andy Cohen on chat show Watch What Happens Live, “That was so long ago, I can’t believe people still make such a big deal about it," but still continued to insist she doesn't know Jennifer when asked if she thought the singer/actress was cool.

“I don’t know her, what am I supposed to say?," she explained. "I’m not going to put on a thing, ‘Oh, we’re all Hollywood, let’s all just pretend we’re best friends because we’re in that land.’”

She clarified she is aware of who Jennifer is but they have never had a conversation beyond a quick introduction so she feels she doesn't know her well as a person.

Demi appears to have referenced the drama around her Instagram comments on Twitter. Hours later, she wrote, "Too tired to... (care)... Up and down, up and down, up and down, up and down, up and down, ups and downs."