Miranda Lambert may earn the award for sweetest birthday message based on what she wrote in honor of boyfriend Anderson East's birthday.

East turned 30 on Monday (July 17), and Lambert decided to turn to Instagram to commemorate the occasion, sharing some kind words about the man in her life. "Rock & Roll Sundays and No Makeup Mondays. My favorite Bama boy turned 30 today. He owns the stage and he owns my heart," the superstar writes alongside a pic stitch of adorable black-and-white photos of the two of them. "Thanks @andersoneast for inspiring me in so many ways. You are a light that could outshine the sun. I love making memories with you."

Watch Miranda Lambert Sing Happy Birthday to Anderson East

The two clearly had a fun time ringing in the momentous occasion, spending the day at Darien Lake Theme Park in New York with Chris Stapleton and his wife Morgane and up-and-coming singer-songwriter Brent Cobb. East and Cobb performed with Stapleton at Darien Lake Amphitheater on Sunday night (July 16). The lake day was just one part of East's celebration. His superstar girlfriend surprised him onstage at the Darien Lake show to perform "Happy Birthday," singing with the hoard of fans in attendance.

In addition to hopping on stage for the birthday tribute, Lambert surprised the crowd again when she joined Stapleton for a soulful rendition of his track, "Fire Away."

The country couple made their official debut while walking the red carpet at the 2016 ACM Awards. East released his first major label studio album, Delilah, in 2015 that includes two tracks that cracked the top 20 on Billboard's Adult Alternative Songs chart.

See Pics of Miranda and Anderson Together at the ACMs