Family and in laws

Hi ladies. I need advice. My hubby doesn't want my son to visit my mom because she lives with her husband who is my step dad. He has had a few issues with him and because my mom and he hubby lives with the hubbys mom. My mom hasn't had a fair opportunity to build a relationship with my son. It is very important to me because I was robbed of that opportunity by my father and grandparents. I always have to be the better person and allow his parents to build a relationship with my son and always ensure they kept happy. This has caused a lot of tension in my marriage and my own family. I've spoken to his mom about it with the idea that she would speak sense into him but that hasn't happened. I guess they are happy they get to be the only ones building a relationship with my son. Please share similar stories.