In the 'gram, the adorable couple look blissfully happy while bundled up on a boat. "Happy Birthday to my Beautiful Wife," he wrote alongside the photo. "I feel like I am the LUCKIEST guy ALIVE I don't think anyone could ever know the Depth, Kindness, and Compassion that I get to experience everyday thanks to My One and Only- You got me til the end baby." Say it with us: awww.
Madden and Diaz rarely make public statements about their relationship. In fact, the last time the Good Charlotte rocker mentioned his wife of two years on social media was April 2016, so that makes this Instagram even more special.
VIDEO: Cameron Diaz Receives Rare Social Media Love Note from Husband Benji Madden on Her 45th Birthday
Talk about showering your S.O. with a lot of love on their special day, right? Swoon.