How do you use the bathroom at a movie theater?

I was at the movie theater last night with a friend. I don’t go to the movies often, but enjoy when I do. I have to ask. When you go to the cinema to see a movie, will you actually leave part of the movie to use the restroom, or do you hold it til the end of the movie? Sometimes I find it hard, but I do manage to hold it and go after the movie ends. I don’t want to miss anything, but also then the restroom line is long too with everyone getting out of the movie at the end.