Who's going as Nickelback's Chad Kroeger and pop star Avril Lavigne for Halloween this year? Actually, Lavigne's ex -- Sum 41 frontman Deryck Whibley -- and his model girlfriend Ari Cooper, that's who!

The couple recently showed off their new Halloween costumes, which features Whibley as his ex-wife, Lavigne, complete with colored streaks in the blonde wig and one of her familiar hoodies. Meanwhile, Cooper donned a Jack Daniels t-shirt, added put-on stubbly facial hair and snagged a Kroeger circa early 2000s blonde wig to pull off her look. Also she's got "red solo cup" complete with Chad's name on it.

The pair posed for a picture that has been making the rounds on Twitter, Perez Hilton, TMZ and various blog sites, but they may not have expected the response they got back from Kroeger himself. The singer, who has been coming back with some pretty witty jabs at Nickelback haters online, saved one of his best responses for Whibley and his girlfriend. He tweeted:

Kroeger and Lavigne surprised the music world this past summer when they announced that not only were they dating, but they were engaged, as well.

So which was better, Loudwire readers? Did you laugh more at Whibley's shot as his ex-wife and her current beau or Kroeger's response? Let us know in the comments section below.