Sorry ~ I didn't mean you as parents making an effort. I was referring to contact cases/issues between parents when they split up and fight over the children...in these cases the parent without contact should make every effort to keep contact going ~ not expecting the other parent to do all the work. I hope this clarifies my previous post :o)
I would imagine you have the stronger position anyway. From what I can see, you are not denying contact at all..as you say, you have offered for them to come & visit which is all you need to do. No court in the land is going to force you to travel the distance to take your son there (I would assume, this may be questionable which is why I suggest the law section). Only if they get to the door & you refuse access may the courts be interested..but only slightly!