So my DH earns quite a lot of money and my SIL and BIL don't earn as much as him jointly and as they have 3 DC they could no longer afford a family holiday (which we used to go on the together with PIL and our 2 DC).
In order that we can still do this for and so DC can all play together, for the last few years my PIL pay their share my DH pays for our family and my SIL and their family! It was on the understanding that they would contribute what they could afford which so far has always been nothing.
I didn't have a problem with this as they are family and our DC love playing together and we all get on great.
My AIBU is that since then financial situations have changed and they have come in to quite a bit of money and we are wanting to move house and save for this (our area is expensive). Nevertheless we had already paid for the holiday before this happened but AIBU to expect that they should at least offer to contribute towards their free holiday?