The Carter's Chord star gave birth to Hutch Robertson Fortney on Tuesday (17Mar15).

Introducing the new addition to fans on Facebook.com, the proud dad writes, "We are officially a family of four. Our latest addition graced us with his presence on Saint Patrick's Day. The whole fam (family) is doing great, and Tug already loves his little brother. Welcome to the world, Hutch Robertson Fortney!"

Robertson and Trailer Choir singer Fortney wed in 2010 and welcomed their first son, Tug, in 2012.

Little Hutch's birth comes as Fortney's former bandmate Crystal Hoytprepares to become a mother, too. Hoyt, who left the group in 2011, is due to give birth to her first child with her singer husband Todd Bray.