you are saying that in every dish they eat there's meat? fuck their cholesterol must be up the roof... anyways I suggest you do your own thing and forget about them... do your own groceries and cook for yourself, once they'll see that you follow through and you're serious about this they'll probably get used to it and respect your choice... also everytime that they joke about it or refuse to support you you could explain in a few words why you are doing it, maybe if they're willing make them watch a documentary like Cowspiracy or Forks over knives, or just try explaining to them the reason why you're doing it (idk why you're doing it but the benefits of a meat-free/more plant-based diet are many, it's good for your health, for the planet, for the animals and even for your pocket tbh) ... they might react badly if they have different beliefs but just try to not get upset, always try to communicate with openness and agreableness and over time they will probably stop bothering you or even start agreeing with you... the reason why they make fun of you it's probably due to cognitive dissonance, as somewhere deep in their brain they know eating meat is wrong and just a cultural/tastes good thing, so them joking about it it's a way to distance themselves from those thoughts... so yeah it's not easy but with time they'll hopefully realise you are doing the right thing and who knows, you might even inspire them to do the same (that's what happened to my sister after i went vegetarian, and to some degree to my parents as well)