Celebrity·Posted on Oct 28, 2012Avril Lavigne's Ex Dressed Up As Her For HalloweenYes, Deryck Whibley — Avril's ex-husband — and his girlfriend Ari Cooper dressed up as Avril Lavigne and Chad Kroeger for Halloween. Oh man, this is so great.by Lauren YapalaterBuzzFeed StaffLinkFacebookPinterestTwitterMail And Nickelback's response: