Nickelback's Chad Kroeger Goes After Avril's Ex Over Halloween Costume

After Deryck Whibley and his girlfriend dressed up as Lavigne and Kroeger for a party, the Nickelback frontman responds.

Sum 41 frontman Deryck Whibley used to be married to Avril Lavigne. Nickelback frontman Chad Kroeger is currently engaged to her. So what happened this weekend was probably inevitable.

According to TMZ, Whibley attended a Halloween party dressed as Lavigne — with his girlfriend Ari Cooper in her best Kroeger costume (Jack Daniels T-shirt, facial hair, ridiculous blonde wig) — and posed for several photos ... one of which began making the rounds on Twitter.

It was a rather good-natured bit of ribbing from Whibley, who split with Lavigne in 2009, one that Kroeger — who surprised pretty much everybody by revealing he was engaged to Avril back in August — responded to with some barbs of his own.

Taking to Nickelback's Twitter account, Kroeger — who just wrapped up a string of Russian shows with the band — fired back, taking a jab at Whibley's career status. "Hey Deryck loved the costumes!" Kroeger wrote. "We were going to dress up as you guys this year but all the parties had celebrity themes."

Oh snap, man. Kroeger would then challenge Whibley and Cooper to "a couples-bowling grudge match," and then resumed his usual activities, which include tweeting about Nickelback's run of Russian shows (Sergei Federov showed up!) No response yet from Whibley or Sum 41. But we'll definitely keep you posted.

What do you think of Deryck and his GF dressing up as Avril and Chad for Halloween? Tell us in the comments!