Bruce Willis' favourite job is making his kids laugh.The 57-year-old actor - who has daughters Mabel, 10 months, with wife Emma Heming-Willis and Rumer, 24, Scout, 21, and Tallulah, 19, with ex-wife Demi Moore - loves nothing more than joking around with his girls and admits he sometimes takes on film roles simply to entertain his children.He told MTV News: "Hopefully my parenting techniques in real life are not about the entertainment of the masses. They are just the entertainment of my children, my four daughters.Â "I get a huge kick out of trying to make my kids laugh. It's a great job to try to be the best job you can."In his new film, 'A Good Day to Die Hard', Bruce stars alongside Jai Courtney as father and son John and Jack McClaine and the action star thinks their relationship was very much true to life.He added: "I get the opportunity to have this father-and-son, contentious relationship that I think really drives the film.Â "It's fun to watch, and it's complicated, and it's a lot like real life, and you kind of know people like these guys, arguing with each other. It's been a running argument."