By Bridget Moynahan calls me during a break in the action from the set of Blue Bloods, on which she's played assistant district attorney Erin Reagan since the show first premiered, in September 2010. She's just finished filming one of the with onscreen dad Tom Selleck, onscreen brothers Donnie Wahlberg and Will Estes, and at least five or six additional Reagans—but the only “fun” part was just being with one another.