You should never cut in line for a movie, and especially during a movie premier. There is almost never a good reason for anyone to cut in line, unless your place was already established. For example you are already in line but you need to go use the rest room. At that point the proper way to handle the situation is to let the people behind you know that you have a quick emergency and you will be back right away so that you have established your alibi that your place was already there.
If you have group of people you are meeting with and they are already ahead in the line then the best way to handle this situation is by asking your friends to save you a seat once they get into the theater (Not too many seats) and to go to the back of the already growing line.
People who cut in line are self-centered and rude. Not only that, usually they know what they are doing wrong and feel by ignoring the people behind them to refusing to look behind them in fear of making eye contact with an upset patron this will make everything okay. they psyche on this behavior is baby like, the though is if I do not see it then it doesn’t exist attitude.
If someone cuts in line in front of you the best way to handle it is to ask very politely to go back to the end of the line since everyone else behind them have been waiting patiently to get in. If they tell you that their group was holding that space for them then again, be nice and let them know that they can wait at the end and meet their friends inside of the theater since that is fair and cutting in front of you was not. If it is still a problem and the line cutter will not go back to the end of the line then find a movie usher and let them know the scenario and we are sure they will handle it accordingly.