This CAN NOT be true, Heidi and Lauren, a DANCE-OFF?

Lauren Conrad and Heidi Montag are now at war ... on the dance floor.Conrad, Audrina Patridge and Lauren “Lo” Bosworth hit Hollywood hot spot Goa early Friday around midnight to film scenes for the upcoming season of their MTV mega-hit.Around 1 a.m. Montag — who tells the new issue of Us Weekly that she has called off her wedding to Spencer Pratt — showed up with Pratt’s sister Stephanie. Though Conrad ignored them, “Audrina came over and hugged and chatted with Heidi,” the witness told Usmagazine.com.Wearing a short, patterned dress, black tights and black leather jacket, Montag and Pratt set up shop at a table next to Conrad and her pals.“Lauren and Heidi were literally almost back to back and not speaking,” the onlooker told Us.Conrad and co then hit the dance floor to 80s music. “Lauren danced with a tall blonde guy and all of them were waving their drinks in the air,” says the on-looker.Ten minutes later, Montag hit the floor to Dr. Dre’s “Next Episode” — only to be followed up a short time later by Patridge and Conrad who took over the dance floor to "Piece of Me" by Britney Spears and "Rumors" by Lindsay Lohan.