I am thinking of leaving my partner and I have explained this to him. I am 30 weeks pregnant and we have a toddler too.
I am utterly overwhelmed. Since we had our eldest his parents and especially his mum has become more involved in our lives: they turned up on our holiday last year without asking or being invited, she is a hoarder and will constantly bring things over for "our house' or for the kids, e.g. when I was pregnant, I very politely asked that she didn't buy a second hand car seat for safety, and she bought 5 secondhand car seats! I came home from work on Friday to find she bought our daughter a dress, clothes, 3 pairs of shoes and makeup and had cut her hair and fed her lots of junk food. Our daughter loves healthy food but she is obsessed with feeding her cakes and sweets, and now lies about what she's fed her as she knows I don't agree.
It doesn't matter how much I ask it to stop or explain the reasons, nothing changes. I feel the same with my partner- he talks but nothing changes. He repeatedly says that I feel very strongly because I'm a mum. AIBU? I feel so alone and scared. He does not stand up for our daughter or me, and when he has spoken to her in the past, he will say it's because it bothers me, rather than because we don't want to parent her that way.