one holiday too many?

In Canada?

He doesn't live in France, that's the whole point. He lives in Canada.

You are both being unreasonable. I wouldn't want to holiday with the in laws once, let alone 4 years! (To be fair I wouldn't want to holiday with my own family either!).
If this is your only holiday then I totally see his point. If however you have something else booked or are planning on booking then I don't think it's unreasonable.

I also think more details would be needed regarding costs, as to me you have a good household income and could afford something else rather than a free holiday with in laws.

She can go on her own any time in the year surely if she wants to see her brother in France.

And if he doesnt live in France (Im assuming he does) then she can see him any time in this country

I think it's fine so long as you also have a family holiday with dh, certainly for the week when he is working. Kids love holidays where they don't have to "do" a great deal and just get to play all the time so it sounds ideal from that perspective with the pool and their cousins. They like returning to the same place. I think it is also important for them to maintain/develop strong links with the extended family.

How could she go on her own if he's working that week? Who would look after the kids while he's working?

Or do you mean on her own with the kids? It says in the OP that he doesn't want her to do that.

Really strange and controlling for your husband to effectively disallow you and your children from seeing your side of the family.

There is compromise to be had. From both parties.

I have ticked YABU because I do think that the two week holiday is too much.
As others have suggested you should go on your own with the DCs for one week and find something else to do for another week.
Neither of you are wrong - it’s nice for the DCs to play with their cousins and it’s nice to have a cheap holiday, but also it’s good to do some holidays with just your family. If the cost of two sets of flights is too much, see if you can find something in the UK.

I'm a bit unclear on some of this.

Two weeks away without him is too much if he doesn't want to be away from the kids that long, regardless of whether or not you think you'd like a fortnight without them yourself. Can you afford:

a) You going away with just the kids to French villa for 1 week, and a completely separate week away some other time?
b) You going away with just the kids to French villa for 1 week and then travelling from there to somewhere not too far away such as northern Spain for a week and meet DH there?

Because those seem the obvious compromise options.

She can holiday with the children independently of DH then don’t holiday he wants as a family after that??

How on earth is she controlling?

He’s working, op and kids go to France for one week, she returns home or meets him for a family holiday without her family.

Again- explain how this is controlling??

She can see her brother any time she likes independently surely?

Doesnt have to mean the family holiday and husbands opportunity for a holiday is hijacked every single year.

When does he get his choice?

Not much evidence of joint working here

You mentioned that you do all the childcare. Is that the same when you are on holiday? Do you feel more supported with childcare when your sister and brother etc are there, so it feels like more of a break for you?
I find it a bit off that your husband doesn't want you all to go when he's working. Would he feel the same if he was carrying part of the caring role when he got home from work?

I think your partner is being selfish not to see how important it is to you to have your family in one place and for all the cousins to play together. These are really formative years for them that they can look back on as adults. I would be really pleased to be at work knowing my children were having a lovely time on holiday. Maybe look at another holiday in the year that would suit your partner more and do that as well. In short I think he is being an arsehole about it.

Why don't you go for a week on your own with your kids, then your partner could fly out, have a weekend with your family and then hire a car and go off somewhere else with the kids for the second week?
Or maybe you could fly direct from the French airport somewhere more to DP's liking and meet him there, halfway through the fortnight?

Yet the op is not controlling at all?

Going to see someone else’s family for two weeks is not my idea of a holiday, especially when it’s been done for the previous few years.
I'm with DH - I’d want a proper holiday…but I wouldn’t stop you going to see your family.
Hopefully you’ll find a compromise, book something that you’ll all enjoy and you and boys visit for a short period of time.
If I worked hard all year and my summer holiday was hanging out with family I’d be fed up.

Go for 10 days and then do a weeks holiday somewhere he wants to go. Sorry but I think you’re selfish to want to go all the to the same place. It’s boring and not fair on him, you are meant to be a family let him pick some places too.

I take my Dd to see her French aunty without DH and I take my son to see his French cousin. DH works more. I have term time holidays. We have the money and flexibility to do this.

If you do too I can’t see the problem!

What about going for 10 days as s compromise.

I find it controlling he won’t let you and your sons go for the week he is working. This seems so odd.

then you fly and meet him somewhere else?

He’s not saying that. OP could always go on her own if she wanted.

Is his counter suggestion that you just all stay home for two weeks? If so, yanbu!

I’m similar to you only my dh would find it b difficult to travel on his own there. He would also hate to be on his own. As a teacher though I get so much more leave I do want to work towards this otherwise we’re just waiting around at home for him!

can be work from there at all?

I’m guessing your partner doesn’t much want to spend all that time with your family because he’s not as keen on them as you are, and there’s little for him to do. He probably feels a bit of a spare part. Maybe he’d like to go somewhere else as a family? That said, I’d insist he did more than half of the parenting and any chores while you were away, since you say he doesn’t normally lift a finger.