I had a very good relationship with my MIL throughout my wedding planning. RIGHT until she freaked out because I was addressing envelopes 'wrong' (not using the right titles). I wouldn't fold and finally had to hang up on her because she was calling me to screetch about this while I was at work. I stopped talking to her completely for the rest of wedding planning. A shame! all because she chose titles as a hill to die on.. I was willing to compromise a bit even though I strongly disagreed with her but it was her way or we were wrong/rude/disrespectful etc etc. In the end she lost out. Her choice.