I think that it is imprudent to deny that the arts, including films have an affect on us. Everything we take in has an affect on us, whether big or small. When you watch a funny movie you laugh, a sad one, you might cry. When you watch a thriller you are scared, and a lifestory -perhaps inspired. The point is, you want to be affected, or moved by a good movie. To what extent you allow this depends, but certainly over time it corrupts. Take violence for example. If my grandmother sees some violent scene in a movie, she will cover her eyes, where as I can watch fine. This shows me that she, who has not watched such violence, is not desensitized to violence, and is still affected by it, where as so many movies have violence in it that I am not as affected, which now that I think of it is a bit sad.
My argument is this. By watching an immoral movie, you have given money in support of it. You have shown your agreement for it. You have given a means for the producers to keep on making such movies. So you have supported a movie which can affect others more profoundly then you might be affected. Secondly, as a practicing Catholic, why would you want to watch that filth. If it truly is immoral, and is glorifying such immorality, shouldn’t you feel offended?
It is like this new movie Angels and Demons. I cannot condone watching such garbage because every cent that goes to them is simply supporting a movie that directly attacks the Catholic Church, and does indeed taint its image in society.