How to deal with my asian in laws?

I am a WF and have been dating an AM for 10 years. In those years his parents would not talk to me for about 6 of them. HIs mothers english is terrible and so she decided it wasnt worth it to even try and his dad would only talk to me when he was interrogating me. We moved in with them for a little while and I thought it might get better. I thought they might finally realize we were serious and try to get to know me. It actually got worse. His mother would follow me around the house and make sure my "white qualities" didnt rub off on their family. I wasn't allowed to touch anything or do anything without permission. It was like a prison. I also found out that they got their other son to spy on me and report back. Well he originally wanted to date me before I went out with his brother and had been bitter about it, so he never reported anything nice about me. We are getting married this year and my fiance has told them that since they aren't capable of being nice to me that they wont play a big role in our lives. Since he has told them that, and he sees them much less than he used to, they have done a 180. All of a sudden his mothers english is much better and she talks to me now, and they are puting an effort in to get to know me and be nice. My question is, should I burry the hatchet, forget everything thats happened and give them a chance? Or do you think I should always keep my guard up and limit my contact with them?