Aww.. I just want to give you a big hug!
There isnt a person here who can answer this question for you. You just have to do things as they come. We don't know the ins and outs of your relationship so its hard to comment.
If I were in her place, I wouldn't mind if you kissed me in the middle of the movie. Thats what the rewind button is for! Sit near her on the couch, cuddle up close and just have fun. Dont worry about anything. Dont push it. I'm sure she'll snuggle up next to you as well.
Long story short, there is no right or wrong time to go in for the kiss. And the pizza thing... Well, you're both eating it, right? So you'll both have pizza breath
Don't worry about it so much!