I seem to remember that the only Biblical grounds for divorcing one's wife (the woman could not divorce her husband) was infidelity, although the civil law in Jesus' time allowed a man to divorce his wife without reason. In the line of this old testament rule, Jesus said two relevant things (that come to mind): If a man lusts after a woman, he has already comitted adultery with her in his heart. Jesus also said that if a man divorces his wife and marries another woman, he has comitted adultery. The book of Hosea has a lot to say about adultery and love overcoming it.

In the context of Jesus' saying, I would say that yes a porn *addiction* is Biblical grounds for divorce, but that divorce is a very bad idea even then. The old testament law says that you *may* get a divorce if the other is unfaithful (using modern, gender-balanced terms), but not that you must or even should. Hosea gives a clear message that you should not; staying together being the higher path. And Hosea's wife Gomer was not just unfaithful, she was practically a slut! But he didn't throw her out, because God told him to love his wife that his faithfulness might help her become faithful. And after many years, she finally was able to heal. You should read the book yourself, it's a good read. So should your wife.

Love in Christ,
~CSL