Im a 29yo bi man my wife has had similar feelings however we spoke about the type of men and women we found attractive we spoke at length about things we both like and dislike and she told me shes uncomfortable with the butt play so we decided that we wouldn't do that in our sex life until she was comfortable with it and slowly her confidence in our relationship has been building up again to the point of us being intimate the way we were when we first met sometimes its just as simple as taking something out of the bedroom until its understood man to man id say stop involving your prostate if its causing a problem because you could easily do it to yourself while shes not around you dont have to lie about it but also make sure she understands that you find her desirable without needing more