Avril Lavigne and Deryck Whibley put on united front

Avril Lavigne and her Sum 41 rocker husband Deryck Whibley put on a united front for the press as they stepped out for dinner in Los Angeles on Monday amid rumours of a marriage split.The couple, who wed in 2006, was alleged to be on the verge of breaking-up, with the National Enquirer claiming Lavigne and Whibley "have been growing apart for months".But the Sk8er Boi singer and the Sum 41 frontman defied critics when they emerged from Madeo restaurant on Monday night holding hands after enjoying a dinner date.Lavigne and Whibley have yet to confirm or deny the reports, and a spokesperson for the couple had yet to return requests for comment as we went to press.