Surprise lovebirds alert: Canadian rockers Avril Lavigne and Nickelback frontman Chad Kroeger are engaged, despite the fact that not many people knew they were even dating. According to People, Lavigne and Kroeger sparked up a romance while they were working together on material for Lavigne's new album but chose to keep their relationship private.

"A romantic relationship blossomed as they spent time writing together," a friend of Lavigne's told the magazine.

Kroeger reportedly popped the question August 8, complete with a 14-carat diamond engagement ring.

"He makes her so happy," a friend of the Lavigne family told the magazine. "Both of their families could not be more excited."

Lavigne and Kroeger have yet to comment publicly on their relationship, but the "Girlfriend" singer did re-tweet a message of congrats from Kroeger's bandmates.

"Congratulations Avril and Chad!" tweeted Nickelback, which includes Ryan Peake, Chad's brother Mike Kroeger and Daniel Adair.

This will be the second marriage for Lavigne. She was [article id="1536426"]married to Sum 41's Deryck Whibley[/article] for three years before [article id="1621834"]they divorced in 2009[/article]. After her highly publicized split with Whibley, Lavigne dated reality star Brody Jenner -- they even got [article id="1643100"]tattoos of each other's names[/article] -- but the pair ended their relationship early this year. This will be Kroeger's first marriage.

Music-wise, Lavigne has said her fifth studio album will have a lighter, more fun pop tone and is expected to be released before the end of the year. In addition to the song written and recorded with Kroeger, Lavigne also enlisted the recording talents of hip-hop production duo the Runners and former Evanescence bandmember David Hodges.