According to People magazine, Dempsey says his twins already have "distinct personalities". The Grey’s Anatomy star added, "Sullivan i has funny expressions and Darby is very reserved and quiet."
Dempsey’s older daughter, Talula, is already in love with her baby brothers. The actor explained, "Talula is making the transition very well."
Dempsey, 41, also credits his wife, Jillian, with encouraging him to pursue his dream of becoming a race car driver.