We stay with our children (Not currently, of course!) and we just chip in with household expenses, paying for a supermarket shop or meals out etc. We buy the children things and when we visit our son we take a suitcase full of gifts, mainly of things you can’t get in the US.
the last time I did something similar it was with friends and when I went to the supermarket with one, I loaded a trolley with 6 bottles of wine and I also took them out for a meal. Usually it is just the latter.
My stepson and DIL are moving to Northumberland soon and have not only invited us to stay when they get settled but have told us to use their house as a holiday base. They'll be at work and we'll go out to different places every day then all eat tea together in the evenings. Even then they said 'no strings attached...you don't have to eat with us every night unless you want to'. Our problem is that we don't want them to be out of pocket and know they won't take any money from us. They're giving us the opportunity to holiday there whenever we want. Has anyone been in this situation? Any ideas how we can pay them without paying them (if you see what I mean)? We've thought about taking them out for a meal and/or taking in groceries. Does anyone do anything else?