Rathbone, whose real name is Monroe Jackson Rathbone V, passed down the family name to his baby boy. After his birth, the actor shared a photo of his dad, Monroe Jackson Rathbone IV, smoking a cigar to celebrate his grandson's arrival on Twitter. "The original (well, the fourth . . .) Bone Daddy!" he captioned the shot.
During a November 2012 interview on the "Today" show, the "Twilight" star opened up about being a first-time dad. "It's the sheer joy ... and incredible fascination of everything he does," Rathbone said. "I have pictures of his first poop. It was incredible. I called all my friends and texted them 'my son's first poop!'"