If you're invited over to someone's house for dinner, it's important to clarify what's on the menu ahead of time, especially if you have dietary restrictions that the host needs to be made aware of.
However, if your host has dietary requirements themselves - such as being vegetarian or having an allergy - you wouldn't expect them to cook something for you that they can't eat themselves, right?
That wasn't quite the experience one woman had though, after she invited her family over for dinner at her house, only to find that they made "snarky" remarks about her decision not to serve meat - because she's a vegetarian.