Photo ExclusivePatrick Dempsey Debuts His Twins!

THREE IS ENOUGH

With three little ones in the house, Dempsey says, "I think we're done now." As for how daughter Talula is handling big sister duties? Dempsey says not only did his 5-year-old help determine the boys' names, she's "very excited and very good about taking care of her brothers."

For more on Patrick Dempsey's twins, pick up the latest issue of PEOPLE, on newsstands Friday.