A few rather harsh comments on here from those [I assume, and I may be wrong] who all have children. Not everyone does like children but is it right to ridicule or label them as selfish, or whatever? Surely the solution is to leave him to his own devices rather than make an issue of the situation.
He probably thought he was OK marrying someone with grown up children and did not think through to the prospect of grandchildren. That in turn is possibly making the situation fraught for him as he will probably have no concept of the bond that exists between the OP and her grandchildren and very possibly cannot understand it.
Just another point of view - but one I came across when working - and on more than one occasion.
I feel I'm failing them - feeling lost
Is this a normal thing? - neighbour using wifi
Only telling GN pals - secret talent