It’s hard to believe the seemingly ageless Keith Urban turned the big 5-0 on Oct. 26.

The milestone birthday prompted wife Nicole Kidman, who turned 50 in June, to pen a heartfelt message on Facebook, saying: “Happy birthday to my husband, best friend, lover, baby daddy and the greatest man in the world. We are so lucky that you are ours. Love you from Nicole Mary, Sunday Rose & Faith Margaret xx.”

Check out the sweet message below.

Keith and Nicole married in 2006 and have two daughters together, Sunday Rose, 9, and Faith Margaret, 6.