While his wife was in labor, Sisto shared some silly tweets with his fans.
"Just bought a teddy bear to give to my daughter 'from' her newborn brother. I'm considering drizzling some placenta on it for believability," Sisto joked, adding: "Don't tell my wife I had two glasses of wine while she had an epidural."
All kidding aside, Sisto let his Twitter followers know that their "unnamed boy is healthy as his mom. Thanks for your wishes."
Five days after his son's birth, Sisto chatted about his family's new addition during an appearance on LIVE! With Kelly Wednesday. "My wife is stressed about [naming him], but I'm hoping something magical happens. . . that makes me think, 'Oh, well of course this is supposed to be his name.'"
"We got an extension at the hospital, but on Friday we do have to go down and put something in, so if we don't have it by then, I think it'll be Baby Boy," he joked. "I think we're gonna be filing extensions for a while. If naming babies is anything like doing homework, then for me it'll take a while to name this kid."
Sisto has been married to Lane since October 2009. The actor's other TV and film credits include Clueless, Six Feet Under, Thirteen and Law & Order.