From PEOPLE Magazine Click to enlarge
Avril Lavigne is in uncharted waters. "I've never done anything like this before," says Lavigne, 29, tucking her legs underneath her as she prepares to dish on being a newlywed. "I've always been very private with my relationships. But I'm comfortable at this stage in my life - and in this particular relationship." Cue her husband of four months, Nickelback frontman Chad Kroeger, 38. "Too comfortable!" he jokes, putting his head on her lap.

Their easy, well-worn rapport may seem surprising given the whirlwind pace of their romance: A month and six days after they started dating, Kroeger proposed - with a 14-carat diamond ring! - and 11 months later on July 1, they wed at a castle on the French Riviera. (It is the first marriage for Kroeger and the second for Lavigne.) When the Canadian singers first met in February 2012 to cowrite a song on her new self-titled album, "it was like we'd known each other forever," Lavigne says. "When he had to leave, I was so sad. I called him up and was like, 'Can you come back to L.A.?' He was like, 'Hell yeah!'"

Though the couple initially kept their relationship under wraps, those around them "could just tell what was going on because all the songs were called 'This Must Be Love' and 'My Little Secret,'" says Kroeger. "Our writing partner must have been like, 'You guys are making me sick.'" (Her album's latest single is their duet "Let Me Go.") Beaming at the memory of their early courtship, Lavigne gushes, "I can't wait to tell our kids about it someday."

In fact, while rumors that Lavigne is expecting are untrue, parenthood is definitely on their agenda. "We both want [kids]," Kroeger says. "We just need to find a time we're both at home to get around to it." That part won't be easy. "Either I'm traveling or he's traveling, so anytime we have a chance to be at home together [in Ontario], we're just so happy," says Lavigne. "With this crazy lifestyle, you relish the time you can be quiet." Adds Kroeger: "I crave the time I can just snuggle up with her and watch a movie." Not to mention enjoy the multicourse meals she whips up. "I've never had anything of hers that wasn't restaurant worthy," he says proudly. "This girl can cook!"

But when their careers keep them apart - like this winter, when they will be touring separately - how do they deal with the distance? "We don't go more than two weeks without seeing each other," Lavigne says. "And we don't drink when we're apart," Kroeger adds. They also don't go to nightclubs without one another. "We don't want to go anywhere that you're asking for trouble," he explains. "It sucks!" Lavigne says with a laugh. "But when you've got something special, you can't be careless with it." Adds Kroeger, gazing at his wife: "This is something we want to cherish and protect."