Demi Lovato falls out with Selena Gomez?

Pop star Demi Lovato has reportedly fallen out with singer Selena Gomez again. She not just unfollowed the "Come and get it" hitmaker but posted a cryptic angry tweet against her.

Lovato, who previously admitted her long-time friendship with Gomez has been strained in the past, sent the rumour mills into overdrive when she stopped following the latter on Twitter Wednesday, reports contactmusic.com.

The 21-year-old singer wrote: "Swimming away from the bullsh*t bye b***h (sic)." but the post has since been deleted.

The duo, who have both sought treatment in rehab in the past, have been friends since they starred in "Barney & Friends" as children.

A source also told gossip website HollywoodLife.com:"Demi doesn't need any extra drama, she's learned from her own recovery to lose the people that bring her down and Selena is to much of a headache."

"The unfollowing of Selena is sending a message that Demi is p***ed. She is sick of Selena's boy-who-cried-wolf mentality," the source added.