Brantley Gilbert is going to be a father of two. The 34-year-old country music singer and his wife, Amber Gilbert, announced Tuesday they are expecting a baby girl in September. "Surprise! Finally, I can share a big secret," Amber wrote on Instagram. "Barrett will be a big brother to a baby sister in September." "It's been so hard to keep this under wraps, so thanks for being patient and waiting on me to share when we were ready," she said. "Bring on all the bows and pink! #babygirl #15weeks #girlsreallydomakeyoumoresick." Gilbert and Amber announced their baby's sex at a party with family and friends. The couple held their 16-month-old son, Barrett, as they pulled a string to open a box filled with pink balloons and confetti. "Oh, I cried!" Gilbert said in an interview with People. "I was so sure it was a boy. I wasn't ready for it to be a little girl -- and man, when it was! I just wanted a healthy, happy baby, but a little girl means a whole other deal." "I am just mush with Barrett," he shared. "I think a girl is going to be a whole new level of everything, and I'm ready. I already know she's gonna own me, and that's okay." Gilbert is known for the singles "You Don't Know Her Like I Do," "Bottoms Up" and "One Hell of an Amen." He last released the album The Devil Don't Sleep in January 2017.