One thing that has helped me deal with narcissistic relatives is thinking about how I would handle the situation if they did they to my child (I don’t have a child, but hypothetically speaking). For example, if I travel 1000 miles and then they all go out to a restaurant specializing in fish and chips when they know I have a contact allergy to fish, I think about what I would do if my child had that allergy and they did that. Then my answer is much more clear.