I feel you are on the right track with your wife, by being present and all..it is a slow process and requires a lot of patience on the part of the person who has less urgent healing needs in the moment. Slow is the way, as always to make it lasting!
Now for the porn, it is really about role-playing and also safe-sex as someone rightly point out earlier, so first step really would be to take away the power of porn over you, for me it happened strangely when I started becoming aware while watching porn, as in I started observing myself observing porn without judgment or guilt tripping myself, soon I could understand what was it that I really wanted and got through porn personally, notion that I am powerful too, through role playing, as it was triggered each time I felt powerless in life, so it is really wasn't my problem than the problem of the powerless part of me, that only knew this way so far to feel powerful and loved once again, so my challenge was to be more present rather mindful in the moment and embrace that vulnerable part of me!
What really spoiled porn for me was one day I found that someone I used to fantasize about, died! and eww...it became ugly. Next I started to think of all the people I am exploiting, just because I want to feel powerful, by having them do things for me! I think of their life stories, and how they fell into prostituting their bodies just to make a living or to feel powerful in the moment, what would happen to them later, and what about their Spirit? That stunned me, I am exploiting them, when I am myself trying to recover from my own exploitation in the past, so am I recovering or merely continuing the cycle? This ruined it for me, as could see them, as mere bodies, which I could see turning into bones and ashes in front of me...and then I realised that one day I would have confront their souls...how I used them to get over my own powerless, rather than healing it through other means... I also imagined their powerlessness, for once! I connected with them as human being rather than just flesh, perhaps I also saw myself and my approach towards sex was merely bodily, not much soul in it, was there?
What if I managed to give someone my loving presence? Physical intimacy is later thing, and becomes redundant if can manage to make another feel loved, through my actions, sometimes a simple gesture or even a look of love... it is a long journey to take love to the dimension of the spirit and experience it there, and then allow it come to the physical level. But for that I needed to experience my own presence first, be my own lover as it were, love myself completely and unconditionally, as only when I can love my completely can I ever hope to share that love with another soul!