Help protect children from gaming harms.

Take our survey

Please or to access all these features

AIBU?

Share your dilemmas and get honest opinions from other Mumsnetters.

Birthday bill split

1000 replies

KnickerlessFatWoman · 18/07/2026 12:55

Last weekend was my mother’s birthday, so we - that’s me, my parents, sister and BIL and their 12 year-old son - went for Sunday lunch. Unfortunately the food wasn’t great, and they ended up taking my main off the bill.

My dad is someone who always wants to treat everyone, so my sister and I decided this time it was our turn and we were going to treat him and our mum instead. When the bill came, BIL asked if we could split it over two cards, but they said they could only take one payment. He paid and I said I’d transfer my share. For the sake of keeping the maths simple on this thread, let’s say the bill was £210, or £35 per head.

Both BIL and sister are crap at responding to messages, so it took me until midweek to get the bank details. I sent over £70 to cover me and one of my parents.

I heard nothing in response, but I was chatting to my mum earlier and she said “Oh, by the way, Katie said you got the money wrong - it was £210 and you only sent £70”. I said no, that was right - my meal and one other. She said, “Ohhh… I think she thought you were splitting it”. I laughed and said, “No, we said we’d treat you and Dad. I didn’t say I’d pay for three meals!”

I don’t really know why my sister couldn’t just have messaged me instead of talking to our mother about it, but that’s not really the issue. Surely she and BIL don’t expect me to pay half the bill? By treating our parents, I meant exactly that - not that I’d pay for them both while my sister just paid for her own family (which is what this amounts to). There are three of them and one of me. If I pay half the bill, sister and BIL have only covered themselves and their child - there’s no “treating” anyone at all.

AIBU for thinking £70 was my share and paying just that?

OP posts:
KnickerlessFatWoman · 19/07/2026 01:34

Calliopespa · 19/07/2026 01:31

When the bill came, BIL asked if we could split it over two cards.

Without specifying the breakdown, I think the most natural interpretation of that is in two equal parts.

I understand why you didn't want to do that, but I can see where their misunderstanding of what you were agreeing to has come from. I don't think it's fair, I think your Dsis sounds pretty foul to have pursued it when it must have been obvious you had had different expectations when she got the payment BUT, given she DID pursue it, it is my opinion that I would have just paid the difference at that point, especially as, after your meal had been taken off, there wasn't a huge amount in it. The reason I would have done so is because I feel sorry for your parents that it has blown up like this over a relatively small sum, given they sound as though they are normally generous.

Splitting over two cards doesn’t necessarily mean splitting 50/50.

OP posts:
Calliopespa · 19/07/2026 01:35

KnickerlessFatWoman · 19/07/2026 01:33

Then why can’t my sister and BIL budget for it?

Don't get me wrong: your Dsis has behaved abominably.

It was just my take that, given your dad so often shouts everyone, I'd have accepted a misinterpretation and put it down to experience - ie; make absolutely certain your Dsis knows what you have agreed to next time.

We can only give advice as to how we would handle things Op. I feel sorry for your parents it has come to this, and, for that reason, that was my advice.

Calliopespa · 19/07/2026 01:36

KnickerlessFatWoman · 19/07/2026 01:34

Splitting over two cards doesn’t necessarily mean splitting 50/50.

No it doesn't necessarily - but without qualification I think that is the most natural interpretation.

KnickerlessFatWoman · 19/07/2026 01:39

ChiefCookandBottlewasher7 · 18/07/2026 15:53

Can you imagine what atmosphere you and your stupid sister created for your parents with this idiotic squabbling? Irrespective of who is right and who is wrong, why spoil the vibe? It is like giving a gift and then crapping all over it. Your parents will be more concerned about your relationship with your sister in the future, as in when they die - surely they hope you will be supporting each other, not quibbling over thirty quid, when the parents are no longer with you?

Jesus Christ. You have taken a fairly massive leap from a minor disagreement over a bill to some kind of nuclear fallout when my parents are dead.

Who the hell even responds to a thread by talking about the OP’s parents dying anyway?!

OP posts:
KnickerlessFatWoman · 19/07/2026 01:40

Calliopespa · 19/07/2026 01:36

No it doesn't necessarily - but without qualification I think that is the most natural interpretation.

There was no need to clarify, as we were told we couldn’t do it.

OP posts:
Calliopespa · 19/07/2026 01:42

KnickerlessFatWoman · 19/07/2026 01:40

There was no need to clarify, as we were told we couldn’t do it.

Yes, I can see that - and actually that was where it all went wrong, because the next step would have been you telling him what to put on your card, which would have flagged up the differing expectations.

But if you post here, people will give advice as to what we would do from the point you are at - and that may differ from the advice we would give as a small claims court.

KnickerlessFatWoman · 19/07/2026 01:42

Recklessismymiddlename · 18/07/2026 15:59

I agree with this. The poor parents over essentially, what was meant to be a treat. The dsis shouldn’t have involved the the mum at all. If I was op, I’d have just said my mistake, I misunderstood and paid up, rather than upset my parents, which this will ultimately have done.

Why should I?

OP posts:
TappyGilmore · 19/07/2026 01:45

What would make me most pissy about the whole thing is that she’s told mum that you sent the wrong amount of money instead of speaking to you directly.

I do agree with the way you’ve calculated it but surely it should have been better clarified at the time.

OneSparklyGoat · 19/07/2026 01:45

Of course you shouldn’t have to pay for anyone in your sister’s nuclear family to dine out because it’s your mums birthday.

Why would she even mention this to your Mum?!

OP, I’ve read all your posts and think you are great, too! It’s given me a good laugh and I’m glad you are sticking up for yourself.

KnickerlessFatWoman · 19/07/2026 01:45

palona · 18/07/2026 16:07

OP, I am very blunt. Why the actual F are you causing such drama over 35 quid? Please tell me you are joking here.

It's not always about who got the last pea on the plate. It's a family outing, just pay half and keep your relationship ok with your family.

I can guarantee you, that if you question this you will have created an awful lot of drama and resentment. FGS pay it. There will be other times when you will pay less.

Honestly.

You sound absolutely awful.

Honestly.

OP posts:
OneSparklyGoat · 19/07/2026 01:47

OP didn’t cause any drama, anyway. There hasn’t been any except if you count dsis dragging mum into it.

Mumtobabyhavoc · 19/07/2026 01:48

No, OP is not unreasonable and her sister (and Bil) is a CF. But, yes, the sister telling their mum that OP got the amount owed wrong is an issue.

KnickerlessFatWoman · 19/07/2026 01:48

burnoutbabe · 18/07/2026 16:11

When was this present decided.

if it was at the meal, then sister went in expecting to pay zero and then politely agreee to pay what she thought was £105 (half of the £210) and then ended up paying £140.

you decided 2 things. you’d treat parents but also that you and her would pay your own food oh this occasion.

(I can see why she is annoyed if agreed last minute, suddenly incurring extra costs for them)

But if I paid half, that would be suddenly incurred extra costs for me! Why should I be the one to incur the costs?

OP posts:
OneSparklyGoat · 19/07/2026 01:49

TappyGilmore · 19/07/2026 01:45

What would make me most pissy about the whole thing is that she’s told mum that you sent the wrong amount of money instead of speaking to you directly.

I do agree with the way you’ve calculated it but surely it should have been better clarified at the time.

It wouldn’t cross my mind to clarify this. “I’m paying for my meal, not your family.”

Who expects someone to cover their people on a check?

KnickerlessFatWoman · 19/07/2026 01:50

TheCurious0range · 18/07/2026 16:13

If you read my previous posts you'll see that actually in my family I have fewer children than my brother but we always split the bill 50 50, I have no issue with it whatsoever , I think counting pennies when you don't need to is more embarrassing tbh. I'd be more than happy to split the cost of my parents having a lovely afternoon with their immediate family, rather than adding up exactly who ate what

🤮🤮🤮

OP posts:
Kisskiss · 19/07/2026 01:50

Agree you shouldn’t pay half , but maybe it should have been split by number of adults ( 210/5) , how much did your nephew eat anyway

KnickerlessFatWoman · 19/07/2026 01:52

ToyStory75 · 18/07/2026 16:18

I would have assumed you were going halves on the whole bill

Edited

Why?

OP posts:
ReadingSoManyThreads · 19/07/2026 01:54

What I realised is that it's lucky you never put it all on your card, as sister would only have transferred over 50% to you, instead of the correct amount i.e. her meal, BIL & nephew + one parent's meal.

I can see from this thread, and your sister's appalling actions in telling your mum, spoiling the treat, that she has form for being an entitled madam.

Glad you are standing up for yourself against all the people who think your cheeky fucker sister is in the right. She's bloody not.

So many people not reading your comments properly too which is annoying, OP never said they were splitting the bill, she said they would both treat their parents, so logically, that means each sister will pay for one parent. Why the fuck are people thinking OP should have paid for some of her sister's/BIL/nephew's meal?!

Also, in terms of "splitting a bill", why does everyone on here assume that means a 50/50 split? A bill can be split with people paying for what they've had. Surely "split down the middle", or "split in half", should be the terms used for people expecting a 50/50 split, rather than split proportionally to who had what.

KnickerlessFatWoman · 19/07/2026 01:55

burnoutbabe · 18/07/2026 16:24

But the present was to save the parents a £210 billi. Not a £70 one?

What does this mean?

OP posts:
KnickerlessFatWoman · 19/07/2026 01:57

Newyearawaits · 18/07/2026 16:25

I would have happily paid half of the bill, we are talking about close family.
Your description of paying for one of your parents doesn't sit comfortably with me.
All seems so business like.

Why doesn’t it “sit comfortably” with you? Why should I cover the entire bill for my parents, but my sister and BIL pay nothing?

OP posts:
ReadingSoManyThreads · 19/07/2026 01:58

KnickerlessFatWoman · 19/07/2026 01:55

What does this mean?

@burnoutbabe perhaps OP's sister should stop being so damn entitled, expecting other people to always pay for her meals.

Rachie1973 · 19/07/2026 01:59

Jeez. I had an element of empathy for OP in the beginning of the thread but I’ve really revised my opinion.

I can’t imagine anyone actually wanting to sit for a meal and eat with someone so very unpleasant.

KnickerlessFatWoman · 19/07/2026 01:59

This reply has been deleted

Message deleted by MNHQ. Here's a link to our Talk Guidelines.

KnickerlessFatWoman · 19/07/2026 02:00

Rachie1973 · 19/07/2026 01:59

Jeez. I had an element of empathy for OP in the beginning of the thread but I’ve really revised my opinion.

I can’t imagine anyone actually wanting to sit for a meal and eat with someone so very unpleasant.

What the fuck?

OP posts:
KnickerlessFatWoman · 19/07/2026 02:03

Newyearawaits · 18/07/2026 17:03

And why does that matter?
These are family!

I know what a family is, thank you.

It matters because we said WE’D treat our parents. Not that I’d treat them and my sister and her family would also be in the room.

OP posts:
Please create an account

To comment on this thread you need to create a Mumsnet account.

This thread is not accepting new messages.