This post really hit a raw nerve with me as I had the same problem with my mum and dad. We used to have a GSD who was always made welcome at my parents although he slept in the garage. My mum bought him a basket though and my dad installed a heater. When we got our first cocker spaniel, Blue, my mum said even before he arrived that if we insisted on having another dog (our GSD had sadly died the previous year) we shouldn't expect to bring him with us if we came to stay. I said fine but we wouldn't be able to visit them although they were still welcome to come and stay with us. This lasted a few months before mum weakened and we were all asked to stay! Since then we have acquired a second cocker and went through the whole performance again with "well we didn't mind the one, but two!" This again only lasted a few months and we have now been there with both. One compromise we reached was that I would bring the dog's crate with me and use this overnight. I have also had a similar reaction from my MIL and again this was sorted by using the crate. Each time I was determined not to lose my cool and politely explained that we came as a job lot, children, dogs and husband or not at all. However I was always happy for them to come to us as I didn't want the children to miss out on contact with their grandparents. Happily all seems to be OK now but will probably start again with no 3!
Liz, Blue and Niamh