I've been quite surprised by a couple of threads on here where parents in-law seems to obviously treat their DIL/SIL differently to their own children.
One where the MIL paid for her SIL to go on holiday with them but not the DIL and one where the MIL spent loads on xmas presents for the son but hardly anything for the DIL.
I find this really hard to understand. My parents have always treated DH as they would their own son. We always get the same things offered to us and the same amount spent on us. I think they would be embarrased to give me say £100 worth of gifts and DH £20 worth. If they said they would pay for me to go on holiday but DH had to pay for himself I would be really offended and we wouldn't go.
My DCs are only little but I certainly plan to treat their spouses as one of the family. It seems horribly excluding not to do so doesn't it?