Actors laughing between takes

Have you ever started watching a movie and at some point throughout, you kind of forget that you're actually watching a movie? Ever been so intrigued by a scene that it slips your mind that these lines were actually rehearsed, the characters are fictitious, the actors are fabricating their feelings and what you're watching might actually be the 15th take? Sure. This happens to all of us and that's what makes a good movie. Well to ease some of the tension off of these intense movies, let's look at some photos of actors when they're not so busy trying to keep a straight face...