To be annoyed SIL showed DS her lactating breast

I'm surprised at some of the responses, given that Mumsnet is the natal home of "boundaries". Surely most posters would hope their SIL (or anyone else) would check to make sure that the demonstration was OK.

My kids (one male one female) know what periods are. But they have never seen me (or any other lady) actively pull her pants down and show the blood coming out. That is disturbing.
We also teach that toilets are private space. I don’t go in front of others. There is plenty you can explain without a live demo.

I dont really see the big deal

I would hope his mum has already covered that with him. Mine always used to accompany me to the toilet as so knew about periods from an early age.

Yes, I agree with this.
I think it was inappropriate.

Ppl saying best to clear it with Mum.....how the heck does that even work?

Telephone: Hello Sandra, SIL here - just got your Johnny with me. He's asking about breastfeeding. Just wanted to clear it with you that it's ok for me to give him the full live demonstration, and not just a verbal explanation. I want to show him how I roll my nipple between my thumb and finger - so he can actually see the milk coming out. Ah you don't mind, Lovely, didn't think you would Sandra! See you later!

🤣🤣

It's obviously not something you do with someone else's child.

Is she also planning to show him how blood comes out of her nethers when she has a period? Because that is natural as well.

It wouldn't bother me personally but everyone has different boundaries. I'd probably want to clear it with the child's mum first.

Its amazing we ever made it out of the caves and didn't all die of shock and horror over each other bodies.

@dodominNo, I’m with you that’s extremely inappropriate! I’d not leave DS with her unsupervised again

Yes, it is. A man might discretely relieve himself behind a tree when necessary and a woman might discretely breastfeed her child in public where necessary.

Both cases are absolutely fine, natural and expected in that context. In neither case is it appropriate to deliberately expose oneself to a nearby child while you do it even to "show them how it works".

No that wouldn’t be odd because bottles are never sexualised and children are never told bottles should be private and if anyone asks to see their bottle they should tell someone.

I know, which is why I'm wondering where the parents were and why the 4 year old was in a position to walk into a room SIL had gone to breastfeed on her own!

Comparing potty training to breast feeding? Nah!

I really can’t see the objection to showing a curious 4 year old.

If you’d said he was 14, I could understand why you wouldn’t like it.

Fine tonne, he’s 4 not a teenager.

No but the OP did say they’re not close.

Ewww. I can understand why you felt annoyed. Totally unnecessary.

This was entirely unnecessary. A brief explanation would have been more than enough, she did not need to provide a demonstration.
All body parts perform vital functions, but some are private for a reason.

My niece may see sanitary products (and bins) at many times in her little life, in her own bathroom, in other people’s bathrooms, supermarkets, public toilets etc. If she asks me what they are for, my job is to say “ask your mum”, and give my SIL a heads up.
Honestly, in the rush to destroy any sense of appropriateness and social boundaries, safeguarding has just fallen by the wayside.

Yes, everybody has breast tissue, including boys. And the child is a child, not a predator.

I still don't see why demonstrating milk flow is odd. Would showing how a bottle works be odd? BFing isn't sexual, and it isn't a waste product that needs to be hidden for decency.

Perhaps you wouldn't be in a situation where your niece wouldn't walk in on you in the bathroom though?
The OP hasn't explained, if she doesn't like her SIL or trust her boundaries, why the nephew was able to wander and walk in on her breastfeeding. SIL hasn't gone out of her way to educate him, she's responded in the moment when he's walked in and seen her.

I think OP is being unfairly piled on, what a shock for breastfeeding to cause such black and white, knee jerk purity spiral behaviour. 🙄

So if we’re all ok with small children learning about natural bodily functions from people who aren’t their parents, perhaps I’ll tell my 4 year old niece about periods and what purpose they serve. I’m so sure my sister in law won’t mind I won’t even ask her before I educate her little girl. After all, periods aren’t shameful, why would there be a problem?

No of course I won’t, because that would be overstepping in something that should be explained by her parents.

Yep. All that - and it just wasn't the woman's place to educate him at all on any subject about the human body. It was fine to answer the question he asked, and then she overstepped, and that's that. The reason she left the voice note was to try to cover her arse as she knew she'd overreached.

Turns out, according to the updates, OP and her husband have chatted and decided to have nothing more to do with the woman, who they have rarely ever hung out with anyway and who has only met their child a few times, and won't bother discussing it with her, or allowing her access to their child to attempt any further boundary breaking.

Best solution going forward really.