Your presumption is wrong, I think, that "she married a gay gay." The "guy" is obviously not exclusively gay: if he were, he couldn't have performed sexually with his wife and fathered two children with her.
You have to conclude that he's a bisexual who decided to dishonor his wife, his vows made before God (if it was a religous wedding) or at least made to his wife in the presence of the whole community; to mis-raise and sexually corrupt his children; and to sow division and discord within his whole extended kindred system--- all in order to cater to his sexual appetite.
He's selfish, dishonorable, and deluded. That word "gay" is just part of the delusion.
I'm thinking more and more that our species is inherently heterosexual simply on the basis of the fact that we manifest sexual reproductive differentiation.
People who want to pursue greater personal sexual satisfaction by trashing their first (and in fact, only) marriage are doing wrong. I don't care whether they call themselves "gay", "bi", "swingin'" or "straight." They are putting their own lusts above other people's well-being, and that is selfishness.
Next year he'll decide he want's somebody else's husband, or maybe somebody else's wife. We can't accept the excuse that it was just his "nature" --- as if he "had" to pursue his own satisfaction --- faith, family, honor and decency be damned.
You may not be aware of this, but lots of gay guys have fathered children with women. The rest of your comment is pointless because you're apparently not aware of that possibility. I'll also point out that -- remarkably -- there's no allegation of infidelity, although infidelity is pretty common in marriages of all kinds. He simply divorced her. Almost certainly a better outcome than the alternative. I wish many cheating straight men and women would have the decency to divorce their spouses instead of cheating on them.