Bobby Cannavale announced the arrival of his son on his appearance on the "Late Show" with Stephen Colbert on Friday night. Baby Rocco was born on Monday to Byrne, Cannavale's partner since 2012. the 45-year-old "Vinyl"actor joked "I'm so tired. I think I've gained 28 pounds since Monday," adding "I'm not kidding, this jacket used to fit so well but I've been eating so much!" Rocco is the first child for 36-year-old actress Byrne, and the second for Cannavale. His eldest son, Jake Cannavale, is 20 years old -- an age difference that prompted Colbert to joke "nice grouping."