Christian newlywed husband to ?

My husband and I have been married 2 years now and recently I discovered he has been and viewing in private. We are strong Christians and have a honest and open marriage as well as a very active life. A few weeks ago I walked in on him . The next day we sat and discussed and prayed about it. He told me that he would not continue doing this out of purity and fairness to me. He also said he felt very guilty about it. We discussed spicing things up even more, and I have been happily giving him free rein in the bedroom. Well, since then I have secretly caught him in the act several times since. He denied that he had to the death. I was already hurt by his behavior, but I forgave him. To see that he still does it hurts horribly. I sat at home and cried for hours until I was sick. Is this worth the pain? Why am I not enough? I'm willing to join him, but he just doesn't even want to discuss the subject. Please help!