Oh dear Sparkygran. I'm sorry to tell you that social skills are another invisible casualty of stroke. I'm not sure how much is stroke and how much is the self obsession of one with a chronic, life changing condition. I know it sounds patronising, but I find if I treat him like a large, challenging toddler, then things are easier. Eg I try, oh how I try, not to shout back when he yells at me in public. I even give him a version of 'Time out' when he gets too angry about something like the the TV not working as he thinks it should. In this case I leave the room while he cools down, not exactly for a minute for every year of his age 
Expecting your food to be given to him, sounds just like this sort of thing, although less embarrassing than being told you are incompetent in a very loud voice because you didn't produce a ticket at exactly the time it was required. And yet he isn't like this all the time or I would be writing this in my prison cell. You have to try to hammer home the point that you do not have a walk on part in his show. Keep taking the liquid refreshment
xx