Im a healthy 55 year old straight guy, married, kids, grandkids etc. Ive experienced something the last few years that has me very concerned. Its convoluted but Ill try and break it down briefly.

I married my second wife 25 years ago, a sweet young woman just out of highschool. The age difference was a concern to many but not us. We raised my kids from my previous marriage, got her through college, supported each others careers and eventually had kids of our own. We are great friends, great partners and for all appearances very happy. But...

Early in our relationship she showed signs of low lebido. I pursued her incessantly but fearing it would become a problem I never pushed hard. We talked about it openly and essentially accepted that we would have to deal with that incompatability and for many years, we did. I kept my sexual advances to a minimum and she in turn complied on the rare occasions when I presented them.

In between I maintained an active practice of regular masturbation. She knew about it and understood and it was never a real problem between us, nor is it now but personally something occurred along the way. Over time I required a more and more powerful stimuli, seaking sexy images and then actual pornography and eventually more deviant fantasies. This was so gradual I really didnt notice but recently I have come to discover that without these images, at least in my head if nowhere else, the idea of generic sex just doesnt arouse me in the least. My wife hasnt complained but has noticed I havent asked for sex in almost two years and frankly, as things are right now, I dont see that I will ever again.

Ive talked to he a bit about the possibility of livening up our sexual encounters but she is a devout christian and very, very conservative where such things are concerned and believes its quite enough for the wife to make herself available to her husband's needs, participation and anything erotic is just not a consideration. The look I got when I suggested anything out of the ordinary (using toys, watching pornography, chatting online while having sex etc.) was truly horrifying and cured me of such notions for good.

So here I am, 55 and progressively slipping down the slope of having to relieve myself by an increasingly erotic diet of sexual fantasy and in doing so I am eliminating any chance of normal sexual relations with my wife. On one occasion, recently, she actually invited some attention (first time thats happened in 20 years and I believe caused by her notice of my lack of interest) and I was unable to perform. The idea of generic missionary sex in the dark just holds no interest for me whatsoever. I finished her off manually and she was mildly satisfied but obviously disappointed I wasn't able to climax. She felt
unattractive and undesirable and was hurt... which is the last thing I want.

So what do I do? Im not sure how to reset my own sexual preferences and somehow make sex with her exciting again, not when compared to the erotic imaginings of a decade or more. She is not likely, not lets just say its an impossibility, that she will ever agree to set aside her inhibitions and get adventurous. So it appears to me we are doomed, eventually the truth will come out and the effect that will have on us may well end our marriage. Help?