To rub his nose in it?

[WhyCantIuseTheNameIWant]

Not literally! Just metaphorically.

When we were with xp, money was alway tight. However, he could always afford a couple of hundred here for a new (not needed) bike, or another hundred for a new coat (the last 4 weren't warm enough...) but anything ds or I actually needed... No chance. Can't afford that!

Fast forward a few years. Xp is with a new victim partner, we are living off benefits, as I am still on unpaid maternity leave with toddler dd. we are financially "coping". We have a few days where dinner is beans on toast. But by being a bit careful, we have had a holiday and some good days out.

Xp has now drained both his mum's and his new GF's bank accounts, by being too lazy to get a job (or too stroppy to keep one...). Everything they do has to be carefully budgeted, aparently. They can't buy any food unless it comes from aldi. They don't have a car. She doesn't drive, and all the other road users are probably safer when xp is on his bike.

Xp has decided he wants to meet up and have a day out with ds. No problem (apart from ds not being keen). He has offered us petrol money and agreed to a more kid-friendly suggestion than the one he came up with.

Anyway, background done, we are meeting next week. WIBU to put dcs in their nice designer clothes? And let them have their expensive toys in the car?
Ds has a great pair of £157 jeans. They are smart and look really good on him (ok, they were £10, pre-loved in the charity shop!) along with a couple of branded t-shirts and hoodies. All just a few quid each.

Dd has a whole collection of pretty tops/dresses. Some gap/next/monsoon... All were too expensive when he was living with us. But they are all nearly new. From the same charity shop. Again, anything from 99p to about £3.

WIBU to make them look nice and smart, in nice clothes for their day out? Ds is desperate to use his Visa card in front of his dad. To buy himself a gift in the gift shop. Because he can...

Not so much along the lines of "look how we waste our money", but more along the lines of "yes, I am looking after dcs perfectly well while you have been bumming around for 3 years."

And no, they won't be wearing pretty white dresses, playing in the mud!

Well that's a very different spin on it than your original post.

It all sounds horribly toxic

Why would you want to inflame things with your X? I think it's a bit strange and pointless to make out you're wasting a fortune on kids' designer clothes when you're not.

If you try to make out you're better off than you are, won't your X resent paying for things even more and quibble about paying entrance fees on the day/future days out etc?

Also I don't think it's good for kids to care about how much their clothes cost. Maybe have a chat with your 12-year-old about why being materialistic and showing off how much things cost is a bad thing. Explain it's bad form and doesn't gain people's respect or admiration. Also explain that when someone else is hard up, it's not very nice to show off your expensive clothes/toys just to make them feel bad.

Ds isn't bothered about what his clothes cost. He is happy in hand me downs or charity shop stuff. Most of his chosen tops are from asda...
He is rightfully upset with x, for taking all his childhood savings.
I am not looking forward to going, but we are going. To try and keep some form of contact.
It's still over a week away, so he will probably change his mind another 10 times between now and then anyway...

Is he your DD's father too? Sorry if it said somewhere but I can't work it out!

Personally I wouldn't do this. Something just doesn't sit right with me about a 12 year old and his mother trying to 'get at' his dad in this way.

You both sound as bad as each other.

So he stole £7000 off your child and you still want to see him let alone have the energy to try winding this fucker up. It sounds like he doesn't give a shit anyway if he hasn't seen the kids for ages, it sounds like seeing him to you is a chance to just try make him look a dick, he doesn't need to be made to look a dick as he clearly is one. If I were you I wouldn't bother honestly and did you get the police involved for the money he stole from your child's account?

They can't buy any food unless it comes from Aldi

Thousands of people shop at Aldi. I know I do and we both work. You sound rather snobbish in your posts tbh.

Hmm sounds a little petty! Your ex has moved on and it sounds like you should too. It also sounds like you're happy that he's made his mum and girlfriend skint.
I would be more concerned about him knowing the kids are happy and healthy rather than materialistic things. It's also not healthy for your son to think like that either

I utterly would. I would enjoy it too.

The best revenge is living well. But the best way is to show him how much happier you all are without him.

He deserves to wallow in the mess he has created. But no harm in showing him you're mess free, contented and looking well

I wouldn't.

What makes you believe he won't expect you to pay for your own entry and petrol when he sees you're obviously doing so well without him and can clearly afford to help him out a bit.
I'm not saying you should help him at all, but don't be surprised if this is how he will see it. After all, he's not hesitated to drain both yours, his DS's, his gf's and his dm's bank accounts. He doesn't sound like he would hesitate to squeeze as much out of you as possible too.
Didn't you learn that the first time around?
I agree with the pp who warned you to be careful in case it backfires.
Whether he pays maintenance or not will have no bearing on him feeling entitled to share in your apparent good fortune.
Do you really want to spend the day saying 'No' knowing it will be your children that will miss out if you don't cough up because if he suspects you have more than enough, it's likely he'll insist he can't afford whatever he agreed and will he really be devastated if your dc have to go without?