Yeah, not knowing you or your wife, this can be hard like you said. But if my husband had come to me about this, and being married that many years, I personally would try to ease his mind and help him with the bad feeling it may have given him about himself. I know this may be no consolation, but if I had to choose scenarios I'd prefer this over him having an affair(s), I wouldn't see this issue as living a lie, I am not lieing I really would try to help him understand it doesn't matter, I'd tell him I 've loveed him for these many years, has been a good parent, provider, etc. and can stay together if he still wished to, but another woman? That is something that would (and has in the real world) driven me crazy, that is "true" unfaithfulness. Ask your therapist/pdoc if there is a way you can talk with your wife about this, maybe the 2 of you can have a consult with a therapist, to help your wife accept this if she wishes, like I said I personally would. Real love doesn't have to be according to standard fairy tale beliefs.
I don't know you but it is important for your general mental and physical being to be who you really are, we only live once (so we know) and I think it would be horrible to have to "perform" (live a different life) just to make everyone happy, your happiness is key
Sorry, just my 2 cents, but I hope it was of some help.
I've been married 25 yrs., kinda grew up together, ha!ha! I can honestly say if he told me what you are debating on telling your wife it truly wouldn't shake my world like an affair had to mine. Honesty is the best policy so they say.
You love her right? She loves you? I feel it will work out then, but that is only my opinion, but consult with your pdoc/therapist about a way of doing it.
I wish you lots of love and luck with this
"darkeyes"

In giving advice seek to help, not please your friend
SOLON