My dad was really great and totally accepted my DH when we met (22 ears ago) and even though we have had problems that were mainly down to my DH, my dad has always been really respectful of my choice. In the last few years we have had bigger problems, and I have talked to my dad about it for support. He is still very respectful but has admitted to not liking certain aspects of my DH's personality that have become more pronounced.
My mum never liked my DH and we were not on speaking terms for 5 years after I married DH (17 years ago). I had a very difficult relationship with my mum as a teen and young adult, so that was also part of it. I have had a reasonable relationship with my mum for about 13 years now, but a few years ago she complained about my DH again and we had NC for some months. I have contact with her again because of the DC, I don't want to deprive them of their grandmother, but also I am older now, and I only have one mum, so I am more willing to put things behind me.
I think what I have learned and what I hope to remember when my children marry, is that it's important to respect your children's decisions also when the are grownups, if you want a good relationship to them, and welcome their partners, find something to like about them.
Having said that, I am heading for divorce. I am never going to discuss it with my mum, as it's still painful that she wouldn't welcome my DH in the family. I don't think I made a particularly good choice with DH, but I loved him, and if I had not married him, I would have been unhappy for years, maybe the rest of my life, as I was so in love. It probably doesn't make a lot of sense, but I followed my heart, not my mind, and that's who I was.