Oh boy, oh boy, oh boy… cat fight a comin’… Miley Cyrus and Mandy Jiroux vs. Selena Gomez and Demi Lovato.

In a YouTube video (made a few months ago), Miley and her BFF Mandy mock Selena Gomez and her pal Demi Lovato.

Miley, 15, makes fun of a T-shirt Gomez, 16, wore and teases Demi, 15, about a gap she used to have in her teeth.

The clip surfaces the same week that sources tell Usmagazine.com that Selena is dating Miley’s ex Nick Jonas (a rep for the Jonas Brothers insists they’re just friends).

Bring it on!!

I think they should settle this the old fashioned way, strip down to their unmentionables and wrestle in some pudding.