HummusForBreakfast there are an awful lot of people who have a very strong cultural awareness who, I am sure, for all kinds of reasons (like being refugees) do not spend 6 weeks a year back in 'their' home country but still have a great awareness of their culture.
A big part of how enjoyable it would probably be, if it happened, would be how much contact the child had with other children their own age while away, if there are cousins etc or siblings who go too, this may make it a more fun experience.
I do not take it as a given choosing to have a baby with a man of another culture means that you will expect to send that child away without you for the summer holidays, nor do I accept that this is always a good thing or something children would welcome. We can only speak for our own selves and our own children in knowing what we will feel would be right.
The point about where the OP met her dh is that they did not meet overseas and then come here and feel the pull to go back etc but he had chosen to live here before they had a family to me that means he has chosen to make his life here. To expect his child to miss the one time when British weather is actually quite nice, and to miss school mates etc, to go overseas ever summer is unreasonable, and in my opinion the OP is not unreasonable to resist this. To claim this is necessary to raise the child bi-culturally is not , to me, correct.
I really don't think there is much point arguing about this, between ourselves Hummus (you seem to want to educate me, which is fine... but...) my dh and I are both English and there are no distant relatives to take our kids for the whole summer so there is no point your convincing of the wisdom of children leaving for the whole summer. Our dd has autistic tendencies and our son is adopted, my children would be distraught to be doing this and there are not relies to do it with anyway! 