A photo of Deryck Whibley and girlfriend Ari Cooper dressed up as the Sum 41 singer's ex-wife Avril Lavigne and her current fiance, Nickelback singer Chad Kroeger, was posted on twitter over the weekend. Whibley dressed as his ex while Cooper donned some fake facial hair and carried a red party cup with the name "Chad" on it at a Halloween party.

We're not sure how Avril's taking it, but Kroeger saw the picture and blasted Whibley over it on twitter.

"Hey Deryck loved the costumes! we were going to dress up as you guys this year but all the parties had celebrity themes haha!" He wrote.

Kroeger, 37, and Lavigne, 28, -- nicknamed "Chavril" -- got engaged in August after becoming close while recording a song for Avril's upcoming album.

Hey Deryck loved the costumes! we were going to dress up as you guys this year but all the parties had celebrity themes haha! -CK

— Nickelback (@Nickelback) October 28, 2012