Congratulations on your decision, I wa sholding my breath hoping you'd stick with the wife.
Ending should be easy. Tell her no and wait it out. The question now is, will you ever tell your wife?Honesty is important in marriage or any relationship for that matter so...best of luck with your marraige, it seems to be getting on the right track.
Ps. How much money do you make? You can send your wife to one of those spa things, those professionals can really work magic with looks if you really need a little shallow indulgence once in a while.
Just a suggestion.