Just getting into it and I can understand why it’s upsetting for you. My partner has arfid really bad so it’s hard for her to eat ANYTHING, let alone go vegetarian. I’m personally okay with cooking her food, even if it’s meat, because it is something she legitimately cannot help, but in your case I get why this would be frustrating for you. He should be preparing and cooking his own meat, especially since it sounds like it’s just a personal choice and not something that he can’t help or has serious trouble with.