So complicated: Chad Kroeger and Avril Lavigne embroiled in Halloween costume drama with her ex-husband Deryck Whibley

Chad Kroeger and Avril Lavigne engaged (Getty Images)

Costume dramas normally take place on Sunday nights and involve tight corsets and heaving bosoms. But a costume drama of another kind has been playing out between Canada’s grunge sweethearts, Chad Kroeger and Avril Lavigne, and her former husband Sum 41’s Deryck Whibley.

Whibley dressed up as his ex-wife to attend a Halloween party at the weekend; while his model girlfriend Ari Cooper went dressed as the Nickelback frontman Kroeger.

Pictures of the pair, both sporting long wigs, Whibley in a hoody with black eye make-up, and Cooper wearing a Jack Daniels T-shirt and leather jacket, surfaced on Twitter.

But Kroeger responded to their actions with a snide remark, tweeting: “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”

“Complicated” signer Lavigne was married to Whibley for three years but they separated in 2009 and divorced in 2010.

She and Kroeger announced their engagement in August after dating for six months.

Canadian-born Lavigne broke onto the music scene aged 17 with her debut album Let Go, garnering hits "Complicated" and "Sk8er Boi".

Kroeger, also from Canada, has been singing and playing guitar with Nickelback since 1995.

Canadian rockers Sum 41 are best known for “Fat Lip”.

Kroeger also challenged Whibley and Cooper to “a couples bowling grudge match” on Twitter.