The couple— who met in 2008 while working together on the Broadway musical, A Chorus Line— announced they were expecting baby number three in January 2019.
“We are adding to the team. We’re going to be a party of five,” Mario wrote on Instagram alongside a cute snap which showed him kissing his wife's bulging baby bump.
After sharing the exciting news, Mario dubbed his wife's third pregnancy as a "Christmas miracle" for their family.
“If it didn’t happen, it wasn’t meant to be. Not part of God’s plan. We have one of each,” he told PEOPLE. “But it got in there! It snuck in, towards the end.”
Baby Santino joins the loved up couple's son Dominic Luciano, 5½, and daughter Gia Francesca, 8½.
Congratulations to the family of five!