You know that feeling you get when you are about to fall asleep but you aren't allowed to because you are at work or driving or in church or some such other situation that strictly prohibits sleep? Your eyelids suddenly become boulders that require incredible strength to lift and your mind cannot possibly focus on any other task besides keeping your chin from hitting your chest. Its terrible.
But, if that feeling happens at the movies with friends, you can totally let it happen. You paid for the movie, right? And your sleeping is not going to detract from their movie-going-experience unless perhaps one of them becomes a pillow and you happen to drool. If you aren't enjoying the movie, then you probably wouldn't be participating in the post-movie re-quote and laugh session anyway. So figure out which friend has the squishiest shoulders (and would be okay with being leaned on) and just take advantage of the non-verbal friend agreement that you can lean on one another. Literally.