Automatically find contiguous movies with Moviesneak.py
mockingeye.com
mockingeye.com
I've seen people do swaps when they realized they hated the movie they were at and walked out, found another movie that ran about the same time and went there. (This tool doesn't sound like it would help that, though.)
helping people rip off a business: fail
Also, even if that's not the case, your presence and use of the facility imposes costs on them, even if "only" small/marginal ones, due to causing further wear-and-tear on the floors and seats, dirt, possibly trash that needs to be cleaned up, and you occupy space (incrementally contributing to crowding), and also (especially in the case of teenagers) may be causing additional noise and immature behavior which annoys or repels adult patrons and those who paid money to see the movie the ethical way.
Are all these additional factors gigantic? Probably not. But to say there's no additional burden or impact on the business or on the community is inaccurate.
Imagine 1000 people all showing up to a movie theater one night, all saying, "We have no intent on paying to watch this movie, and in fact, if you do not let us in free now to watch one, we guarantee we will not pay now or later, anyway. Therefore, you might as well just let all 1000 of us in to watch the movie." No theatre could stay in business for long allowing that to happen. Why? Because the business has to PAY MONEY for rent, wages (to sell tickets, clean theatres, operate the projectors, etc.), supplies, taxes, legal compliance, etc. Where does that money come from? Paying patrons. Therefore, instead, it is more likely that the manager would indignantly call the police on their asses. In essence, those folks are unethical parasites, regardless of what excuse they come up with.
This is about the same as getting a free refill from a soda fountain at a place that doesn't explicitly post that they allow free refills. If they object, the soda fountain can be relocated behind the counter with few issues or inconvenience to just about anyone.