Demi Lovato fans are trolling one of the star's friends on social media after she shamed Demi for not attending her birthday party. This morning Lovato tweeted out a cryptic message to someone telling them to "stop existing in [her] life" and said that person should have thought twice about "publicly shading" her.

!twitter-embed(https://twitter.com/ddlovato/status/992025021282369536)

After some investigation, it appears the whole thing boils down to Demi skipping her friend Marissa Callahan's birthday party. The birthday girl let her disappointment at the snub be known online and Demi fans were not here for it.

Lovatics took screenshots of apparent messages on Callahan's social media account that appear to be directed at Demi.



Twitter

This one, in particular, got lovers of the "Tell Me You Love Me" singer irate and caused them to troll Callahan in defense of Demi.



Twitter

Lovato basically said "sorry not sorry" for skipping the party and is publicly moving on.

There is a lesson to be learned here folks, don't mess with Demi or the Lovatics.