Why is this so common

I think it’s just a figure of speech to lots of people. Not actually ownership of the baby.

Oh boy, in the Caribbean we call our grandparents mama and daddy lol

It's irritating. I stopped it. They've had their own already. What sealed it for me was my mil also making decisions for me etc like my baby was actually theirs and I was in the background.

I say pick and choose your battles lol. If you think your MIL is doing it maliciously to get under your skin, speak up. If she’s doing it bc she just loves your daughter so much, I say let it go. Only you know how you feel about it so if it’s absolutely driving you bonkers of course say something.

My sister calls my son her baby and my husband’s cousin calls my son her child. It’s just done in a loving way.

I think who its coming from makes a difference as well as the persons character and demeanor towards you in general.
My mom, my grandma, and my best friend call my baby their baby and honestly i dont love it but it doesnt bother me, but i notice if my mil does it it really irks me.
someone else said to pick your battles, and i have to agree here. with stuff like this i can just ignore it and put my feelings aside, i choose the battles that affect my kids wellbeing or our boundaries as a family.

I don’t think there is anything wrong with it… my mil does it, my mom does it too. my sisters do it as well. I do it with their kids. I think it’s just a way of expressing love, not so much ownership.

I mean it's the idea that it's the village's baby...like especially if you are getting lots of help from the person who is calling the baby their baby. You aren't raising a kid alone usually and it doesn't mean they don't know who the biological parents are but when you have support from many people then that kid is loved by many and of course they develop an attachment. Now if they aren't helping at all then I think it's weird af and they don't get that right. And if you don't like it say something

My mother in law does this!! It's cringy to me, but I just ignore it.

It pisses me off too! I really do not like it, regardless of who it is, friend, family. I care slightly less if the person doing it actually helps out and is part of my ‘village’. But my village consists of mum, sister and best friend. And none of those girlies are the ones who do it.

This morning I saw the funniest thing on Facebook!

A girl I’m friends with recently had a kid and she obviously also hates it when MIL says ‘my/ our boy ’ because her MIL commented ‘our boy’s growing so much’ and she replied by tagging her hubby and asking if he had grown in the last few months or whether it was just their child.

I thought that was a clever way to respond, it’s witty and funny but also lets them know that their child isn’t your child, it’s the child’s father.

My grandmother always called me “my baby” growing up and I liked it. There wasn’t any confusion that my mother was my mom, just a cute term of endearment

Is this something you can overlook? I understand lots of people say it to a baby that's not theirs, but as the baby's mom if you don't like it then they need to stop. I don't mind it. But lots of moms do so absolutely pick your battles and maybe this is one that you're picking.
For me, I was not ok with my kid calling his grandma "mama". I put an end to that within the first month baby was born. Absolutely not. I don't care if it's a part of the culture, I am the mom and it's disrespectful to me that MY baby calls someone else mom. For you, if you feel strongly about someone saying "my baby" to your baby, then I think u should absolutely stop them. Good luck!

I’ve told all family members who said it, not to say it. “You mean MY baby?” is what I’d say. I do not have a relationship with anyone in my life where it would feel okay for them to refer to my child as their baby.

my baby isn’t even born yet and all my MIL talks about is how i’m carrying “her hero” and she always calls him “my little rhino” or “my baby” smh. when my husband posted our maternity pics she comments that too. my own mom doesn’t do this, it’s always the MIL’s which makes it 100x more annoying lol

My finances aunts call my MIL my sons mama, yeah it’s very annoying lol

ok this made me cackle 🤣

If it bothers you then yes have it addressed. I would have your partner speak to his mother about it. I think it’s weird too. And I’m almost 100 sure she wouldn’t like it done to her when she had her son. It’s like they lose their minds after their grand kids are born.