Can't believe my DD

I too did wonder how your DD's new partner gets on with the children and whether or not they have a good relationship.
If they cry when they come back from their father could it be they are a little afraid of him, is he strict or abrupt because he can't be bothered with small children and they annoy him? Does he have any of his own with an ex-partner?

Without asking any leading questions and keeping it casual you could perhaps find out for yourself what the children feel about this.

rose DD and the father are still married. He has no ex's or other children. I genuinely believe the oldest prefers being with his dad. For the opposite reasons to which you refer.
He is very laid back, lives on junk food, they always come back dirty and father spends a lot of time working on cars, which boys love to help him do. If younger one is upset his solution is to give him a biscuit!!
DD insist on good manners, feeds them home cooked meals at the dining table ( he doesn't posses one) reads with older one ever night. Is very tactile with them.

Easy to see why a 6 yr old might prefer to be with dad and just the reasons for my concern.

FlicketyB no that is not the case. The plan was for them all to move to Scotland. DD and partner had discussed child care, school for the boys etc. He certainly didn't suggest the boys stay with dad. It was only when DD told the dad of their plans and his immediate reaction was "You do what you like, but your not taking my children with you" that they had to rethink things.
Her partner told her he wouldn't ask her to come without the boys. DD has decided for herself that she will.

Thank you all for your comments. It has made me see that maybe this is not the total disaster I first thought.

I think the thread has run it's course

ninathenana I know you have drawn a line under this, but I just wanted to say that I have re-read my post and it is a bit confusing (even to me with my convoluted mind)

I meant: does DD's current partner have an ex and other children, and is he a bit abrupt and can't be bothered with little children, perhaps a bit impatient? I thought that could be why they like being with their Daddy. But it seems not which is good.

I can see that young children may well like slobbing around with Dad, no routine about washing, teeth cleaning, reading etc - and eating junk food not the healthy option at the table. So a year with him could undo any good that DD is managing to do with them.
I don't think he can stop her taking them, it is still the same country (for the time being anyway).