That sucks OP. Historically, I've been pretty lucky with theater experiences and crowds, though I went to see IT last year for a second time and it was one of the worst experiences I'd ever had in the theater. Like, unbelievably bad.
Was a group of young teen girls who were just talking constantly and then laughing and being over-the-top loud during any scene. And when they were just generally chatting, it wasn't like they were whispering, it was like they were just straight up TALKING over the movie. Eventually, someone in the audience had enough after ~40 minutes or so and they were removed by ushers. The only time I've ever actually people removed from a theater. It felt great though, lmao.
But then in the same audience, there was also these two girls sitting dead center of the theater, and over the course of the movie, they probably took over TEN SELFIES WITH THE FLASH ON. Like, who the fuck does that? What the fuck is wrong with people? I'm the kind of person who doesn't let shit get to me/make a scene in public, but man, I almost made a scene with these two different groups of people because they were both incredibly obnoxious and inconsiderate.
So yeah, people being jackasses ruining a film people paid money for is super annoying.