Avril Lavigne, Chad Kroeger of Nickelback Credit: David Livingston/Getty Images), Jordan Strauss/WireImage

Secret romance! Avril Lavigne is officially off the market.

The 27-year-old singer's rep confirms to Us Weekly that she is engaged to Nickelback frontman Chad Kroeger, 37.

The news comes as a complete surprise to fans. The Canadian couple has kept their relationship a secret, but did tweet about their collaboration on Lavigne's upcoming album back in February. "Bro'ing out with Chad Kroeger in the studio," Lavigne tweeted with an adorable photo of Kroeger hugging her.

"Things just clicked real quick. We were just gonna [collaborate on a] couple of tunes," Kroeger told K104.7 in April. "And then she wanted me to sing on one of them and then we just started flying on all these different songs.

This will be Kroeger's first marriage and Lavigne's second. She filed for divorce from Sum 41's Deryck Whibley in October 2009 after three years of marriage. In January, Lavigne split from former Hills star Brody Jenner after nearly two years of dating.