When I lived in the NYC area after dinner coffee and dessert was an absolute must and to not offer was considered an insult. But, now that I am in Pa it is not to be expected here. In fact, here in the Leigh Valley parents often time Sleepovers and Birthday parties so that all meals will be fed at home by the parents. In NY parties and gifts were extravagant as everyone took turns throwing big parties to take turns hosting nice events to be enjoyed by everyone, here the name of the game is to do as little as is humanly possible and every little event is scrutinized for being a 'gift grab'. I have had to tone things down since moving here so I'm not seen as too showy and keep with what is customary here.
It's all in the culture so it's only rude when it is to be expected. I don't know how things are where you are going but if you have to ask I would probably guess it will be a no.