Benji Madden is pretty smitten with his wife, Cameron Diaz.
In celebration of the actress' 45th birthday on Wednesday, the Good Charlotte rocker shared a sweet message on Instagram, along with an adorable photo.
"Happy Birthday to my Beautiful Wife. I feel like I am the LUCKIEST guy ALIVE," Madden captioned a photo of himself and Diaz snuggled up to one another on a boat. "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."
The 38-year-old musician continued to gush over his wife of two years, writing: "You got me til the end, baby."
PHOTOS: Cameron Diaz and Benji Madden Enjoy a PDA-Filled Lunch Date
Diaz is clearly as crazy about her hubby! While she rarely speaks about her personal life, she couldn't help but praise Madden after a Good Charlotte show last summer.
"One of my favorite things about being married, is how much pride I take in my husband @benjaminmadden," she wrote. "He makes me proud everyday.. One day it might be how generous and giving, another how gentle and thoughtful. Or when he is fiercely protective of the people he loves and cares about... And single day I am so incredibly proud of his integrity as a human being."
WATCH: Cameron Diaz Talks 'Surprise' Marriage to Benji Madden -- 'I Didn't Think It Was Something I'd Do'