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In what will surely be the winner of lamest feud ever between Canadian rockers you actively dislike and/or are indifferent to, Avril Lavigne's current and former loves had a dustup over the weekend.

It all started when her ex-husband, Sum 41's Deryck Whibley (also known as the short guitarist from your favorite band in eighth grade) seemingly decided to dress up as his former missus for Halloween, complete with a twee hoodie and a blond wig with multicolored strands.

At his side was girlfriend Ari Cooper, decked out in a goatee, peroxide locks and a beer cup labeled "Chad" to channel Avril's fiancé, Nickelback frontman Chad Kroeger.

What should have ended with Whibley and Cooper evaluating what went wrong in their lives to take them to this sad, pitiable place instead headed into absurd territory when Kroeger actually responded to the picture.

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

Dissed by the guy responsible for foisting "Rockstar" on the world? That's gotta smart. Being in Nickelback? That's gotta smart even worse. Being forced to look at Nickelback's Twitter feed? Well, the joke's on us, now, isn't it?

Lavigne split with Whibley in 2009 after three years of marriage. "We've been friends for a really long time," she told Ryan Seacrest in 2010, "and we always will be family."


Guess the celebrity in costume

Kim K's mermaid costume

Heidi Klum's elaborate Cleopatra costume