Deryck Whibley Dresses Up As Ex-Wife Avril Lavigne! Girlfriend Dresses Up As Chad Kroeger!

And the Most HIGHLARIOUS Costume Award goes to…
Deryck Whibley and Ari Cooper!!!
The Sum 41 singer and his model girlfriend dressed up as Deryck’s ex-wife Avril Lavigne and her new fiance — Nickelback‘s Chad Kroeger!
Deryck really knows how to work a frown! Ha
Think any other celebrity’s Halloween costume will be able to beat the hilarity here??