Proving they're still the cutest couple in country music, Tim McGraw took to social media on Friday to wish wife Faith Hill a happy 51st birthday. "From the first time we met, I knew that she was the love of my life forever," the 51-year-old McGraw wrote alongside a collage of several photos of Hill, including a couple of adorable childhood pics. "No matter the ups and downs, the happy and sad or the good and bad. She’s so special and so loved by us. Happy birthday, my love." He ended by declaring, "When I wake up next to you in our eighties, I’ll smile at the life we’ve built." Aww!