This isn't the first time that Lovato has remarked on the rivalry between these two divas. Earlier this month, she commented on another Instagram post, which was a video snippet of Lopez talking about the feud and showed her solidarity with her friend.
"This is why I posted what I did. Jen keeps it classy but I'm not afraid to say s**t," Lovato commented on Thursday.
"The woman is mean for no reason. Extremely talented? Yes. Superhuman? Possibly. Unnecessarily rude? Absolutely," she added.
Watch Carey claim she doesn't know Lopez in the video below.