As my T always said....
Its not the feeling that's wrong, but rather what you do with it.

What married couple hasn't at one time or another thought of being in the arms of another person? What married couple hasn't had a fantasy of another that made them feel oh so good? What married person hasn't wondered if they might be happier if they were with a different person?

I think you just need to allow your self the right to love your wife while still giving your body the benefit of being a sexual being with sexual feelings that do and will get stirred at times... but by all means do this with in the marital vows you took with your wife, and if change is needed then she must agree with you or there is no change.

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BTW - I too have dealt with the feelings you are talking about today and while I may enjoyed the sexual thrill they gave - I never took part in the pleasure they offered... and I'm glad to say that my husband and I will be celebrating our 24th Anniversary in four months (old desires no longer included).