DLS, "nailed" in this case means skewered in a more conversational way, by the female co-worker who accused the wife of using men sexually.
Captain, bluntly: If your wife has no interest in you, but keeps you around because you're a chauffeur/gofer/helper/prop, that sucks in my opinion. On the other hand, if you've sussed all this out and decided to be her chauffer/gofer/helper/prop, it's obviously not going to change. She's willing to be married to a guy she thinks is not good enough to be her lover, and you're willing to be married to a woman who thinks you're not good enough to be her lover. Since you agree on this point, nobody is going to do anything about it.
Unless some part of that analysis isn't actually true. For instance, maybe your wife, like you, would rather have you as a lover and a full husband, but doesn't know how to get there from here. Or maybe you'll get fed up eventually and show her that you don't accept the situation.
