deryck-whibley-and-ari-cooper-Halloween-Avril-Lavign Published October 29, 2012 at 400 × 487 in Avril Lavigne Ex-Husband & GF Dress as Avril & Future Avril Lavigne Husband For Halloween [PHOTO] Avril Lavigne’s ex-husband Deryck Whibley and his girlfriend Ari Cooper dressed as Avril and her fiance, Nickelback singer, for Halloween.