If there’s one thing I hate, it’s mezzanine leaners. If you are seated in the less-than-ideal mezzanine of a theater or an arena, it is best practice not to lean forward so you can get a better view of the action. If you do so, you will block the view of the people sitting behind you, which will encourage them to lean forward and do the same thing to the people behind them. Best practice is to sit up straight and get the best view possible with the cheap seats you purchased. Depending on the stage show/ball game you’re watching, you’re probably not going to be unable to view the action for the entire time. If nobody is sitting directly behind you, you’re free to lean to your heart’s content. It’s unlikely an usher will stop you from being a mezzanine leaner, but that doesn’t mean it’s acceptable to do so.