I have a friend who describes himself as "meegan". He's straight-up vegan in terms of his regular diet (not because of ethical issues, but because he feels better eating that way), but if he's eating out or at a friend's house, and they're not serving vegan fare, he'll eat whatever is on offer.
It seems like a rational way to go about it.
and then
> still periodically eat meat
I'm sorry but you shouldn't call yourself a vegetarian.
I understand your point, but I don't entirely agree. I think if someone's primary diet is vegetarian, calling themselves that isn't unduly misleading even if they eat meat on occasion.
But it may be a difference between being "vegetarian" in terms of participating in a movement and being "vegetarian" just because you prefer to eat that way.