Husband chat

He's not technically my husband as we are not married but felt easier for this post. Tonight I spoke to him (for the millionth time) about how hurtful his mothers behaviour is for me. We saw her on Xmas and we are seeing her again just after new year and I dont want to. Everytime we see her she says or does something triggering. He said to me that mum will never change. He said he knows she's very negative and that he copes with her behaviour by not letting anything absorb. He just lets everything slide. He said shes my mum and i love her and i love you and ive always got your back. Be polite but dont take anything she says or does seriously. Be very surface level about stuff. I guess he was meaning information diet. He said he knows she loves our child but we wont let our child experience what he and i have. I've come away from the talk feeling validated but also kind of... deflated. Not sure why. Just needed to post it.