jeeez louise........... the nude body only became dirty after god told them it was. Before that they didn't think "sex" when they say each other nude. Any psychologist can tell you that the quickest way to make something titilating (dontcha love that word) is to forbid it, cover it up, censor it or ban it. It's worked for years with the puritanical religious and the JWs are no different.
It IS possible to look at the human body objectively. Here is the thing, we as humans are not attracted to everyone. And even if we do find someone attractive it doesn't mean that we are unethical enough to take advantage of a situation.
So in my humble opinion, neither the doctor nor you is committing porneia (which is a crock anyway in my opinion) unless you took advantage of the other person by attempting to arouse them or encouraged your own arousal at their expense. Things that are not consensual are immoral. Again, my opinion. You know what they say, opinions are like a$$holes, everyone has one. And hey, obviously I have more than one!!! LOL
Having said that, I understand that you were trying to trap him in his own reasoning (so to speak), and it is kind of funny when that works.
Gretchen