If its a private box, you will find that the vermin that sit in front of you will be looking for clues as to whether you are a blue or not. They will give you plenty of verbals, ranging from a simple 'do one bertie' to death threats. Just laugh it off.....it never amounts to anything as inevitably they have to rush off before the end to catch the train/plane back south.
I have had some great fun over the years bating them, however i always did this out of the view of my host whom i have a great deal of respect (even tho he's a RAG). My mate even got one bloke so wound up that he head butted the glass! I think he regretted this as its was pretty thick stuff.
My top tip would be to turn the TV in the box over to another channel, they used to like to turn around and watch the replays of the goals, especially there own. For maximum impact i would wait to change channels until a goal is scored (don't forget to do it in full view of the vermin as well). They will luv this, I promise!
My mate did this once and you should have seen the response, funny as fuck. From what i have seen, they are all mouth and little action. You should be fine....but don't quote me!!!