Justin Bieber didn't invite his grandparents to his Believe film premiere. Only one set, mind. 

While the singer was accompanied by his mother's parents, Bruce and Diane Dale, to the film's first official showing in Los Angeles on Wednesday, his father's side of the family weren't as well represented.

Justin's other grandparents, George and Kathy Bieber, were at home in Canada, but told RadarOnline they would like to have been invited. When then asked about his relationship with the teen star, George reportedly "sighed heavily" before saying: "I really don't want to talk about it."

The reason for the absence of George and Kathy - parents of Justin's father, Jeremy Bieber - could be down to them previously saying they "live on different planets" and the singer has got "too big for his britches". And Gandpa Bieber wasn't just referring to Justin's pants being down around his thighs.

George told the: "He never calls us, and now I sometimes think he doesn't care. It does make me sad, as right now our lives are pretty desperate. I can't work due to illness, so there is barely any money coming into the house. His grandma has a bad back, too, but works like a dog hauling huge bags of paint powder 40 hours a week."

He also took aim at Bruce and Diane, parents of Justin's mother, Pattie Mallette, saying: "For them, nothing seems to be too much trouble, and he buys them new houses, cars, luxury holidays, anything they want - but for us, nothing."

Justin was raised by his mother as a single parent - which may have something to do with it, but they both maintained good contact with his father, who went on to marry and have two more children, and is now a part of Justin's team.

The good news for the Bieber elders is that 19-year-old Justin said at the premiere he is planning to take that break after his new album Journals is released and will spend more time with his family, saying: "I wanna get to know my family more. I've been away so much, I've missed a lot."