'A Good Day To Die Hard' director John Moore has described Bruce Willis as a "very good" father and insists the action legend took his co-star Jai Courtney under his wing on set.The 57-year-old actor has four children - nine-month-old daughter Mabel with his wife Emma Heming Willis, and grown-up kids, Rumer, 24, Scout, 21, and Tallulah, 19, with his ex-wife Demi Moore - and he used his parental skills to help his co-star Jai Courtney while shooting the action sequel.Speaking at the movie's premiere at the Empire cinema in London's Leicester Square on Thursday night (07.02.13), the film's director John Moore told BANG Showbiz: "Bruce and Jai got on like a hose on fire on set. Bruce is a very good dad in real life, he's very protective of his kids and very decent and very realistic. He keeps things very real with his own family. He was very fatherly to Jai on set. He's a decent guy, and Jai being Australian has a great sense of humour so they worked well together."Â John insists the rapport on set between himself, Bruce and Jai - who play father and son John McClane and Jack McClane in the movie - was great and the good relationship shared by all the cast helped make the film great.Speaking about life on set, he said: "We lived together like The Monkees! It was fun, we hung out. At the end of the day we've all got a job to do, we all did it, people were professional and courteous to each other. All these things made the movie special."Bruce was joined by his wife Emma on the red carpet and other attendees included Jai, Sebastian Koch - who plays the film's villain - and former Pussycat Dolls stars Ashley Roberts and Kimberly Wyatt.