Vegetarians and Vegans, Have you had others disrespect your dietary choices and how did you respond?

One of my nieces has been following a vegetarian diet for a long time. The other day a male friend of hers offered to cook dinner for her. Kind of a date, but nothing serious at this time. She gets there and he has a nonvegetarian meal layed out. The only thing vegetarian was one vegtable dish. She turned around at the door and left. I heard the story and my first comment was you don’t have to worry about the relationship progressing any further. Is it common for others to assume you’ll just throw aside your dietary practices to suit them? I couldn’t believe the disrespect this showed.