I just take dinner to the movies, haha. My fiance and I sneak meals in all the time

Yesterday we took in Quiznos. I even had room for both of our drinks!
If I want a snack, I'll take a piece of fruit, pop my own popcorn or I'm thinking of taking asparagus next time to snack on. To avoid munching on the popcorn someone else might have, I chew gum as soon as I'm done with my snack
Taking whole meals in can be tricky, but if you have a big enough bag it's quite easy. Just don't make it obvious and hide your food underneath papers or something, There was on time I had to open up my bag, but everything was hidden so we got in

If it's my turn to pay for the movies, I keep everything out in my hands and don't open my bag until I get inside.