My partner recently became a vegetarian (after watching 'Earthlings') WOOHOO!!! In my past relationships and before my current bf became vegetarian I only prepared vegetarian/vegan meals and when we eat at home we would eat veggie unless he bought and prepared meat for himself which was extremely rare. I'm a pretty good cook and I'm outspoken about my disgust for the smell of meat cooking and how I fear food poisoning with it being around the other groceries so its easier for them to just eat veggie. All past bfs said they loved my cooking and didn't miss meat at all so maybe I've been lucky but honestly I don't think I would have been with someone who insisted on bringing meat into the house and didn't enjoy eating vegetarian food. When we'd eat out it'd be a different story.
Now that I've become even more passionate about veganism I don't think I could be with someone who isn't at least vegetarian and very thoughtful about what they consume. Just like I coudn't be with a smoker. Yuck (and stupid)!