My sister in law is vegan. She is the most normal person about it I've ever met. She doesn't talk about it unless it comes up in conversation in a normal way.
She doesn't proclaim it, because its part of who she is it isn't the whole of who she is. She also understands that other people's choices are theirs and she doesn't need to convert them, or defend her own position.
When we have family gatherings, we try to accommodate with food offerings, but she says we don't need to and always brings her own food and extra to share. This is important because she's self sufficient and doesn't expect anybody to adjust their life to match her choices. Likewise, between diets and allergies we as a family just always ensure people know what is in what.
These are just simple examples. My point being, I don't think of her as vegan. I think of her as my sister in law. Be a normal person and its all good. If its not, then that's not on you. There are jerk vegans and jerk non-vegans. Don't be a jerk. Don't tolerate jerks in return.