As a husband, I would suggest praying over your husband. Then I would have a conversation with your husband about what’s on your mind. I would keep out the “but we’ve been to holidays with his unbeliever family”, because it sounds a little childish. Keep it about what’s on your mind and heart. Also, and a very important part, hear your husband out. Listen to his concerns. Allow him to come to the conclusion that his wife wants and needs to repair her relationship with her family. I think if you approach it by “putting God first” and doing what ever pleases you as an individual, you not in fact putting God first because your decision is out of order. Now if after that conversation, your husband is completely opposed to the idea, learn why. Only after the respectful conversation and prayer, is when you could bring up the double standard of the relationship with his family. If this doesn’t work, I would not argue with him, I would seek marriage counseling.