"Every year only gets more fulfilling," the musician wrote on Instagram, celebrating both a decade of marriage with Diaz and her new movie 'Back in Action'

Benji Madden is in proud husband mode. In a sweet Instagram post Friday (Jan. 17), the Good Charlotte guitarist praised Cameron Diaz on her return to acting in new film Back in Action, as well as marked their 10-year wedding anniversary.

The Good Charlotte guitarist and the actress have famously kept their relationship private since they began dating in 2014 and married less than a year later.

Benji Madden shared a tribute for wife Cameron Diaz celebrating their 10th wedding anniversary and the actress' return to the big screen.

Benji Madden is celebrating two milestones with one cute couple photo of him and Cameron Diaz. On Thursday, the Good Charlotte rocker belatedly commemorated the couple's 10-year wedding anniversary while also praising his wife's return to acting with a very sweet—and very rare—post on Instagram.

Cameron Diaz and Benji Madden have been vocal about their family's privacy, making Madden's post all the more exciting for fans.

Benji Madden has plenty of reasons to celebrate his wife, Cameron Diaz, including the couple’s 10th wedding anniversary and her return to acting. “This is my QUEEN. I celebrate this BAD ASS WOMAN. Wife,

In honor of 10 years of marriage earlier this month, Benji Madden shared a rare selfie photo Jan. 17 with wife Diaz, gushing over his "queen" in the caption.