There are two criteria here that I feel should be satisfied before I could determine the "rightness or wrongness" of this situation.
First, I would say that as long as your wife is well aware of this activity and is fine with it, then the first criterion is satisfied.
Another consideration in determining whether this is right or wrong is how you go about posting the pictures of yourself. As long as you are posting your nude photos on a site where these types of photos are expected (so that someone who does not want to be exposed to such things will not stumble upon them accidentally), then the second criterion is satisfied. But if you are springing these types of photos on unsuspecting women, then it is akin to flashing/indecent exposure. Consent on all sides is important. In other words, if you consent to posting nude photos of your body, if your wife is okay with it, and if the women to whom you are showing the photos are willing to look at them, then who cares what anyone else thinks?