Son recently separated from controlling wife

If your former daughter in law has all the power over the children that you say she has then you need to get her on your side by all legal means possible.

Try to make friends with her so you can better support the children and your son.

Could you give examples how she is controlling?

Your son needs a lawyer and custody agreement. That's his first priority.

Rather than have any confrontation with boys she as always let them have free rein with anything meal times,food,clothes,bedtime,whether they attend partys,swimming lessons etc.Once married she insisted on moving in with parents(under pretext could save more towards deposit)which was never go to be as parents needed their financial contribution to keep family home.She has always someone to help out and would not attempt basic trips with boys on own but instigates numerous activities throughout the day when its Daddy day it's as if she wants him looking to fail by not sending party clothes,presents , sportswear etc.He has asked she let's him know in time for him to shop after work before the day required.Its as if she is scoring points but doesnt consider it important for the boys.My son is happy to provide what/when he can rather than the boys go unprepared.We do communicate with ex on occasions re boys only .It was a joint decision they didn't involve solicitors and tried to sort shared care between them she has got things to suit herself.But on positive note the boys are relaxed and happy in dads small cosy home and he is certainly in a better state mind other than anxiously waiting for nasty rude comments and avoid confrontation with ex family in front boys.

Well he needs to go shopping for decent clothes for them in advance, don't wait for things to be arranged take the initiative and make sure they always go home in the clothes they arrived in or otherwise he'll be forever buying new ones and never see the ones he's bought again.
Just because they reached an agreement re the kids between themselves that doesn't mean he can't go to the family court to get it tweaked and made official.

Your son needs to document, document, document.

Looks like he will be better off without her.

I agree that he needs a set of clothes at his house suitable for the activities he does with them. We had a similar situation with the clothes and the mother sending child in tat. The child had a complete set of clothes kept at the father’s and it only went home with her when she would soon be grown out of it.
I also agree that he needs things on an official footing or she will keep taking liberties.
It is good that your uson is coping well and the children are happy when staying with their dad.

Thank you for your advice I feel so helpless as he cannot see how she is playing him and to be honest because he is happy having the kids he will tolerate the rubbish she and family throw at him.He did buy basic clothes pjs school tops,pants socks joggers hoody only from primark as money by then was tight she wasnt happy and told them they didn't have to wear them.Birthdays family bought better outfits and sent them home thinking it would help over xmas time these havent been seen again and over xmas they arrived in mismatched summer clothes.I have been to sales n bought 2 new outfits each which will stay here for when occasions arise.I think as time moves on things will get worse and he will need some good advice and maybe a support group where he can meet fathers in same circumstances.He obviously has little money so
is reluctant to involve solicitors she is self employed and has always done plenty cash in hand jobs. Anyone been in same position and can offer advice.

Your son is the key to give stability for this kids.

He must get a lawyer and stop playing her games.

Get legal advice sooner rather than later.
He doesn't have to act on it straight away if he doesn't want to (although I would). He could think it all over in his own time. But he needs to realise her behaviour will in all likelihood get worse.

The rest is being practical and planning ahead.
Second hand clothes and toys left at his place.
Second hand duplo or Lego to be given as birthday presents in a drawer + cheap cards ect.

Take control now for the children's sake.

Your son is happy with the arrangement so I would suggest that you support him in that decision. Racking things up and involving lawyers is a lose lose situ except for the lawyers. Keep an emergency gift supply and some cheap cards, make the most of the sales. A couple of sets of clothes are essential anyway. Things will settle down eventually.

I don’t see where involving solicitors will help in any way other than make a big hole in his pocket so my advice is solicitors are not necessary at this stage
She is not stopping him having the children that’s the only important part She isn’t stopping you seeing them
He has his own place so all he needs is some organising I agree with others a full set of clothes to be at his and STAY at his they go home in what they came in likewise a set of toys/ bikes whatever needed stay at his and are only played with at his they will soon get used to what is played with and where not ideal but definitely workable
Bed and meal times are done to his liking, how she parents them in her time is up to her and not your business unless you suspect any abuse and you don’t
Yes Daisymae is right it will all settle down and they will have their routines I have it my own family older children but a week on and week off and clothes at both houses, two prefer it at one house but happily go to the other the older one prefers the original home but goes to the other one when she wants (she’s an older teen) it’s a lot better for them than living in a war zone or in our case a ‘frozen desert’
Kids adapt very quickly and they will understand mummies rules and daddy rules Keep friendly as you can you don’t want any privileges withdrawn or communication cut

The children will soon adapt to different rules in two different households. Keep everything you need for them at your sons house. Don't tell her where they were bought or how much. They are happy and relaxed so its not a problem.

Also does the taxman/benefit people (if she is claiming any benefit) know the cash in hand.

I am so grateful to you all,having someone to talk with gives me some peace from the constant worry about my sons future and him maintaining stable relationship with his sons who he adores.He has plenty of patience and the time with them is spent playing games they do have a good assortment of toys(not new)and we have put together a few emergency cards/pressies in the event of partys,they have swimwear on hand and wellies for parks and walks.I suppose that is why they appear so happy at Daddys.After a long sleep last night they had a leisurely morning when he put them in his clothes before we all (aunts uncles and cousins)went for a walk, kids on scooters, then for tea where they ate all and life was great.I now realise his and our stability makes them happy.His ex doesnt mean harm to kids she has always said no boundaries is best way to parent but the constant rowing within home must impact on boys.Following previous divorce and relationship problems she has kept work related issues to herself .Will see what New Year brings.He does document things lateness , change to arrangements,kids not ready/play at friends etc if further down line it shows a pattern then he may consider family court to make arrangements official.

Sorry that your DS' marriage failed, Party4, and that the transition between XDIL's home and DS' isn't as smooth as might be desired. Glad that DS seems to be managing, though, and that your GSs are happy when they visit him.

IMO, your posts make it clear that they need a set of clothes that are kept at DS' house, period. I also agree that DS needs to take the initiative and plan the activities for the days that the boys are w/ him, so that XDIL can't control how they spend their time together, etc. If he's content to let her plan the events, then he'll have to put up w/ any inconveniences this causes. Thoughtless and unfair of her, but I doubt she's going to change any time soon.

Of course, there would have to be an exception for any extracurricular activities the boys are enrolled in. IMO, he should find out exactly what their schedule is where extracurriculars are concerned, so it never comes as a surprise. But, of course, that, too, is up to him. If he's comfortable going from day-to-day, week-to-week, letting XDIL tell him what's going to happen as they go along, then that will have to be ok.

I'm glad he's documenting things and that he's prepared to go to court if ever he feels there's a need. Official arrangements might make things a lot more organized, but I understand that solicitors are expensive, etc.

One thought re/ activities. Children get invited to parties and events by people not necessarily privy to the visitation schedule and are involved in activities that predate the split (or at the very least, their interest in said activities may predate it). They will pick up it if there's any tension about those and eventually feel guilty or upset to feel "in the middle". I think you're wise to support those plans and have things on hand to support the boys even if their mom may be less than helpful in that area

Your son needs to either start divorce proceedings or persuade her to. Once this is done there will be a period of mediation at this they will have to reveal all their financial details and discuss access to the children. If she has kept the marital home she will need to make sure he receives some financial compensation. They will eventually reach an agreement which ensures neither of them is disadvantaged. They will only go to court if they cannot agree and that's when it gets expensive. If you or your son have friends who have divorced you should ask around to see who is a good solicitor they do vary. He should then be able to get basic advice for £50. It only gets expensive if one of them contests the divorce.

There is nothing that can be done, the parent that has custody has control and this deliberately uncooperative attitude is very common and you just have to live with it as best you can.
It happens the other way round as well I know one father who makes his son change clothes when he visits regardless of how he was clothed before, it’s a ritual.

No wonder we have so many kids with messed up heads.

It is very rare these days for one parent to get sole custody, custody is usually shared and mediation deals with the access arrangements. Sole custody is usually only granted where one parent has been negligent or absive.

Thank you for all your advice it helps in keeping me fair in thought and not one sided. the welfare and future lifestyle of my DS and GSs have become our constant worry.

We found it easier to buy more clothes for the children which stay at our house. That way we could make sure the children were decently turned out when they were with us. We also have different behaviour expectations than their mother. The children adapted with no problems. Like most children they were already used to adapting their behaviour at school so this wasn't a new situation.

We didn't need to involve a solicitor but it might be worthwhile him having a half hour freebie session in case money raises it's head in the future. Just so that he knows where he stands if it happens. DH ex threatened him with the CSA until he pointed out that under their rules she'd actually get less money from him each month.

I'm sure this isn't happening but never let anyone say anything against their mother not matter how they want to. Particularly when the children ask why you/he/anyone does something differently to their mother. If ours ever say anything we simply tell them that people do things in different ways and no one is right or wrong.

We are always polite when discussing her and family and as she is now trying to score points by over indulging in treats etc we always say How lovely that will be fun. My son is not in position to over indulge due to finance but time and simple childhood pleasures are plentiful .His sons appear to love their time with him and after him being at near breaking point worrying finding and complete furnishing home for them he is at the moment happy and children being children once the treat occasions have passed they never mention them again.Maybe that's what upsets her as both son and Gs appear happy with little they have.

Why is it down to mum to provide presents for parties on days he has them? Are they communicating what is needed in regards to sports kits etc? Personally I would expect the father to provide what is needed for the children on the days he has them. When child support is worked out it usually takes into account the days they are with each parent. She doesn't actually sound too controlling either. I think time is needed to let the dust settle and importance needs to be placed on maintaining a good Co parent relationship even if it is one sided x

Quite happy to provide presents if given more then 24 hrs notice when he can call somewhere on way home from work.After being dropped on now keeps items for partys, in fact has picked some good sale items and had delivered from Amazon.As one gets used he looks out for replacement then let's his son wrap n sign a card of his choice.