If anyone is struggling to convince their husband/SO that they need to side with you get the book ‘The Seven Principles of Making Marriage Work’ by John Gottman.
In the solvable problems section he has a small bit on how a man should deal with MIL-DIL tension. He explains how every time a husband sides with his mother over his wife he is chipping away at their ‘we-ness’ or their feeling of being a team leaving the wife feeling like an outsider.
I finally got through to my now ex about this yesterday and he finally understands. For a long time we have been working on strategies to be closer whenever his mum undermines me because he wouldn’t go further than telling her not to but she continued anyway. We also had the problem that she would get him on the phone after an incident and convince him she made the right choice – hence I felt an outsider. Last week I confronted her myself via text and she told me I should thank her for being more attentive to my child than I am. He thought this was okay because I ‘provoked’ her by suggesting she twisted what actually happened and therefore her response was not unreasonable.
We decided to be done a few days ago but yesterday I read that to him and he finally seemed to understood that all our interactions with her were infected with him siding with her and I felt like a guest in his family, all the time. There has been tension for 4 years over his mother and he’s definitely enmeshed with her so been very defensive and horrible to me whenever I wanted boundaries.
Sad to have gotten to this point and finally got through to him so telling others as it might help you! The book in itself is great but those few pages about the need for a man to side with his wife are just so well written and not attacking the man at all which is why it think it finally got through to him. Hope it helps someone!