AIBU to expect MIL to arrange DH’s 50th birthday gift herself?

Don't think of it as revenge @WithTwoGiantBoys - think of it as mirroring his effort. If he is then upset by that, it's a good jumping off point for a discussion about why it's OK for you but not for him. If he's not upset by that, you know going forward significant birthdays aren't marked and arrange your own treats, if that's something you can live with.

In which case she should have politely said that she did not want to do it and been clear about it. No need to be horrible in doing so, just clear.
She has made a suggestion but MIL wasn’t keen on it.
I agree with you, if MIL is able to go shopping she might want to get something else.
But the fundamental problem is a lack of communication. Not asking why, what, or how about ?

Does she know how to look for and book experiences?
Does she believe she's out of touch with what's available?

Getting her to pay for your present to him kills two birds with one stone if you don’t want to rock the boat too much. Tell her he’d love a weekend away / meal out and can she transfer you the money. Then when he asks what you got him tell him you got him the exclusive personal concierge service of being his mother’s birthday agent.

YABU.

Not because you want MiL to buy her son's present herself but because you're even posting about it when your DH can't be arsed to buy you anything.

You are hurt and resentful about the way he reats you but are unable to match his energy and you're stressing over being unable to be clear with MiL that she needs to do her own footwork?

Neither of these things are actually hard. To MiL you just say "MiL, you're going to have to sort DH's present yourself if you're going to get him something. I do not have the time or inclination."

Then take a deep breath, think what budget would be reasonable for DH's 50th and then spend that on something for yourself. Admire it everyday (or if it's an experience, keep a photo on your lock screen) and start to appreciate and value yourself a bit more.

Just sort out a voucher for The Pig or another hotel, or theatre tickets to a show you would both enjoy.

As your husband didn’t buy you anything for your special birthdays and your MIL doesn’t like you anyway, I wouldn’t be buying a single present!
Your MIL has time to sort her own and your husband doesn’t deserve anything. Stay firm!

Time to stand firm OP. Match their energy. Your husband clearly isn't interested in birthdays ... especially yours, so don't bother with him. At least don't put yourself out for him. Just tell mil you are not available ATM due to other commitments.

Why on earth would you get him anything then? Bonkers.

Either directly refuse or buy a spite gift.

Like a trip for two (that your DH will love) and say its for the two of them to do together. if she hates the spa, buy that. If she hates cake, get an afternoon tea. If she hates books, get tickets for them tickets for a literary festival, if she hates golf, buy them a round.

Maybe she doesn't care why her MiL wants her to book it because she doesn't want to do it! If the MiL can't navigate around being able to buy this kind of present then maybe she needs to pick something else to buy? Or ask someone else for help? The OP does not have time, even if you think she should.

I just refuse. I have enough to do wrapping my own presents 🙄

Amazon voucher for an experience - then mute her

@WithTwoGiantBoys Tell her that you can help her get a gift card/voucher for his favourite restaurant (irl YOUR favourite ofcourse). Then take him there for his birthday- pay with the voucher and it will be your bday present as well.

I dont even like it when when people send my gifts from amazon and i'm expected to wrap them

Well that’s on them. I love having a thing to do / experience present. Off to the theatre with the DDs on Saturday - my Mother’s Day present.

OP don’t start this nonsense with her. It will escalate, Mark my words <looks at own mother>.

Picking an experience and choosing it online does not take hours. Not really. If you know your way around the internet.
She may not know how to navigate such things. If the OP doesn’t ask her why did she want her to do it she will never know why MIL has asked if she can book it on her behalf. A simple few questions might get some answers.

If someone asked me to do something like that, like I suspect the majority of people they would ask why do you want me to do it out of interest ?

She needs to do it herself, she’s being lazy. Sympathies as my mum often tries to delegate these kind of shit jobs to me. Like your MIL she has literally all the time in the world but can’t be bothered

Very restrained response. I commend you 👏🏻😂

Then why isn't she just asking for ideas, rather than expecting OP to organise the whole shebang? It is a burden.

She is asking you because you are his wife and she thinks you will know better what sort of experience he might prefer.
Not because she wants to ‘burden’ you with the awfulness of choosing one, a date and paying for it. Which she will pay you for.

Not really, a whole different kind of thinking is required. Plus the OP will be getting something back from posting here.

If you feel the need to get him something after he did nothing for you, then I would thoughtfully wrap a box containing just a note

DH here is an IOU to match what you got me for my birthday, as I appreciated it so much! Enjoy!

Petty maybe, but oh so well deserved.

I'd go back to her and say 'apparently my husband doesn't want to exchange presents any more so I'm following his lead. If you want to get him something then you are going to have to decide what you want to get him and then get it. I don't even have the time to think about this at the moment.'

Don't be polite.

Just say "I have tried to tell you politely that I do not have the capacity to sort this, this week. I still haven't bought a present myself. I am not your secretary. If you do not sort it, you can explain yourself why he hasn't got a present".

And send.