When I saw the thread about vegetarians and fish, I thought ooh something I can post on, having had experience of people dishing up fish for me when I go for dinner. I agree with the OP ... what's wrong with saying I don't eat meat but I eat fish?
Innocent and lighthearted until I realised I'd found myself in the middle of a big barney!
Just reread the thread and I've got so say Milady ... I don't understand why you are getting so upset and defensive. There's no ganging up that I can see, just people making the (very obvious) point that someone who eats flesh (however infrequently) isn't a vegetarian. It's a no brainer really.
If you consider yourself a vegetarian why do you eat fish/meat twice a year? You obviously don't like it that much or you'd eat it more. I'd say you're mostly vegetarian but have the occasional lapse and leave it there.
Some of us don't eat fish/meat cos we don't like it (I'm in that category), some of us make a conscious decision not to eat fish/meat because of the animal welfare aspects. I'm not quite sure what category you fall in to? You can't be eating flesh twice a year to be social surely, nor because it's doing you some good in terms of dietary requirements.
It really isn't anything to get upset about or fall out with people. You eat what you want to eat and after 35 years of whatever it is, you decided you will occasionally partake of a bit of flesh. It's your choice and vegetarianism occurs for all sorts of reasons and comes in all kinds of degrees from all out touching nothing of animal origin (the vegan end of the scale) to folks like me who eat dairy, to the 'vegetarians' who some of my dinner hosts cater for who eat fish, only I'm not one of them.
We can call ourselves whatever we want, but I've got to say posting on a thread like this saying I'm a vegetarian but I eat flesh twice a year, was kind of asking for some of the responses you've received, don't you think?