02/28/2007 at 03:00 PM EST
It was the extraordinary moment Patrick Dempsey had been awaiting for nearly nine months: the birth of his twin sons. And yet as wife Jillian was readied for her cesarean section at an L.A.-area hospital, Dempsey couldn't shake the feeling that somehow the whole scene was oddly familiar. "It was funny because the doctor asked if I wanted to help with the delivery," says Dempsey, who's used to scrubbing in thanks to his role as Dr. Derek "McDreamy" Shepherd on ABC's smash medical drama Grey's Anatomy
The new dad cut the cords – both of them! – and kept his cool throughout. "I was watching everything that was going on [with the doctors], and you see a lot of that in the show," he says. "It was a bit surreal." So was the twins' big debut. "When Darby came out, he had short blonde hair and a wider face," says Jillian. "Sullivan has Sid Vicious black, punk-rock hair." And yes, the tots' tiny follicles are already beginning to develop a telltale curl. "They already have my hair," says the proud dad. "That's a good thing."
Even better is day-to-day life for Dempsey, 41, since the Feb. 1 arrival of fraternal twins Sullivan Patrick and Darby Galen. The boys join big sister Talula, 5 – and their dad is still adjusting to his tripled brood. Returning home from the hospital, "I felt like we'd outgrown the house already, and we just moved in!" says the actor, sipping a mid-afternoon mimosa during a break from a fund-raiser in San Francisco for Breakaway from Cancer, an organization he became involved with after his mom's triumphant battle with the disease. Appearing sur- prisingly well-rested in jeans and a blazer (and showing off family photos on his PDA), Dempsey hardly looks like a man in the throes of new-dad exhaustion. What's his secret? "It's much harder for my wife than for me because she's having to pump or nurse," says the actor, who gifted Jillian, 41, with diamond studs after the birth. Plus, having been through the newborn cycle once, "with Talula she was colicky, and we didn't know what to do. These guys," he says of the quick-to-snooze twins, "are amazing."