I'm so sorry for your experience! We were lucky. My father held my mom's hand through her incurable illness all the way through the end even when she told him that he can leave her because he was still young, to find a happy ending with someone else and if he stays, things are going downhill anyway. He didn't even consider leaving, let alone an affair. Though he could have because she'd hardly ever find out about the affair. I admire him so much for it.