“The audience is so in the heads of these characters that the biggest jeopardy in our show is often when one of the relationships in the Irish Catholic family looks like it’s going south.
“For instance, Erin [Bridget Moynahan] and Frank are increasingly in conflict the higher she moves up in the DA’s office.”
The actor added: “The best family dinners are when we argue.
“When the family gets together, the audience usually knows the character’s problems, so they’re going, ‘Boy, if he brings that up, that’s not going to sit well with Erin.’ They want the Reagans happy, that’s the key.”
Blue Bloods is available on CBS in the USA. A UK release date is yet to be announced.