Trying to cage my felion

I have recently moved back into my boyfriends parents house. When I say "back" I mean, I had already lived here once, but after a very extreme argument, we moved into my parents house. While living at my mums place, I decided to buy my bf a kitten for Christmas. Bf has never had a pet in his life.. his parents are cruel cruel people...The plan at the time was for us both to save rapidly and move into our own place.. This did not end up happening.. We decided to stay at mums for a while longer until we figured what to do. After a few months, bf got annoyed with the confined space provided in my parents house compared to his two story mansion at home. After more than several arguments, with a lot of persisting from BFs parents, I agreed to move back to his place. "But what about the kitten?" I asked. His parents offered for us to bring her here with the hope of being kept in a cat run outside during the day while no one was home. The offer also stated that she would be inside at night while we were at home....

So we move back and feel happy with all the space we now had again. A cat run had still not been purchased, as we had not done any research. After about a week of no cat.. I asked "do we need to have the cat run here before we bring her over?" and of course what do you think the fathers reply was?

It has now been four weeks.. The kitten has been living at my mums for around 7 months now. We purchased the cat run last week and the plan is to build it tomorrow. This morning I woke up and thought.. 'what if we go out at night time?'. I turn to my partner and ask "If we go out at night, does she have to stay outside? Or is she allowed in?" BFs reply was "She will probably have to stay outside". Well I was beyond annoyed at this point. It has been raining everyday for the last 4 weeks, and not only do I already have to encage my pet, but now I am being told that she will have to be left out there at night time until we return home.

So now my plan of action is to begggggg my mum to keep her at her house just a few more months. It is now April, I plan to be living in my own place by January. I am hoping the cat run place, will refund BFs parents and life will go about almost normal. I cannot bare the thought of her in this little cage starring at a brick wall all day. I have been with my partner for nearly 2 years now, and I am very prepared to put this kittens well being first. I am guessing this will cause quite an argument with the parents and BF. But I really do not care anymore.