Heidi & Spencer Are A "Nightmare" To Deal With

Heidi Montag is scheduled to perform at the Miss Universe Pageant at the Atlantis resort in the Bahamas on Sunday night, but it sounds like she (along with hubby/pro moocher Spencer Pratt) are both being a royal pain in the butt!

An insider told Page Six "They're a complete nightmare. Heidi has missed many rehearsals [while] Spencer tried to demand that the hotel pay him to lay by the pool [after he and Heidi were comped on the cabanas]. The Atlantis laughed in his face."

A rep for Montag has denied that the newlyweds are acting like spoiled divas, releasing the following statement: "It's absolutely untrue. She's been rehearsing in LA five days a week for the show, and Spencer hasn't spoken with the Atlantis."

Hmm, who do you believe?