Behaviour when visiting his parents

Hello guys, so basically I need advice on what do you think it's appropriate in this situation and if you have advice. My bf and I are together for almost an year now, we don't live together( he's not from the city we live in so basically he is under rent and I on the other hand, am born in this city so I still live with my parents- I'm 24 and work and support myself financially but think it's stupid to pay rent when you get along well with your family and have a house), so next week he's taking me to his hometown for the second time and I wonder what should I do about the following: the first time I met his parents we again were visiting them, they were very kind and made a lot of meals for us, they didn't let me even wash my dish after dinner, I offered to help, his mother told me "I got it", then I responded "are you sure you don't want any help", and she still refused, they only"let" me be a part of preparing the barbecue. So I wonder how I should behave the second time around, on one hand, we don't live together,we are their guests and maybe it's only natural they "spoil" us and prepare everything, on the other hand- I don't want to seem unwilling to help or lke I'm not a good housewife( even though I'm not a wife yet haha). With my bf it's the same, I mean we have never cooked together- we eat out and when we're at this place we order, because in my point of view it's only natural that way, and once we start to live together we will do it ofc-but for now I cook for me in my home and when we meet I don't want to bother with that again, I just want to have fun So what do you think I should do, should I be more insisting or just let them be good hostesses and act like I'm on a holiday ?