Will Ferrell gets carried away when building Lego creations, and admits he sometimes orders his son to leave the room rather than help him so he can concentrate.
The actor - who voices two charters in 'The Lego Movie' - loves to play with the children's building blocks, which are sold in sets allowing users to build intricate designs such as cars, boats and jets, but admits he sometimes gets a little too engrossed in the building.
Will - who is father to Magnus, nine, Mattias, seven, and Axel, four, with his wife Viveca Paulin - said: "I have had moments where I have sat down to help my son build the Millennium Falcon [craft from 'Star Wars'] and have literally told him to leave the room because I have to finish this one part. He can join me later. And I literally build it like for an hour. But then it's like, 'My God, what am I doing?' "
The funnyman also admits he gets the same desires to then smash his creations back into pieces that his children have.
He added to USA Today newspaper: "There is a part of me that wants to re-create the picture we see on the box of whatever we bought. There's a certain feeling of accomplishment to build the perfect Eiffel Tower. And yet smashing that thing to the ground and starting from scratch, that should be supported, as well."
Will is not the only star to enjoy Lego, as retired soccer star David Beckham has recently admitted he likes to play with the blocks, and they help to "calm him down" after a stressful day at work.