Can you guys suggest any way that we can a keep a girls attention span fixed for same amount of time as your own?

I will explain an example: If i want to go and see a screening of The Godfather at one of those cinemas that re-screens old classic movies, how i can make the girl i am with sit through the film because Godfather is long movie? How i can make her concentrate and understand the movie so i don't have to keep explaining to her what is happening and what means. last time i had to constantly explain to this girl what was happening throughout a long movie; which i hate the most because i lose my own concentration . Who knows some suggestions?