Since when does a guest get to demand that the hostess prepares a special dish just for you? Then to top it off he's griping about it, as if he's entitled to make demands on the hostess.
Talk about being a special snowflake.
I'm a Catholic. When I was young we weren't allowed to eat meat on Friday. Strange I know, but it was considered a way to show God you were willing to make a sacrifice in His name.
Since a lot of parties and events occur on Friday this came up often. Sometimes, people who knew you were Catholic would serve an entree you could eat, but often they never even thought of it, because why would they?
We NEVER suggested to anyone that they make something special. You simply ate the potatoes and salad, or ate a hamburger bun with tomato and mayonnaise.
Honestly, there are a lot worse things in life than not being able to eat some of the food at a party.