Breast enhancement, or rather: plastic surgery in general
Until recent years, I've always been a strong opponent of plastic surgery, particularly breast enhancement. People should just appreciate the nature of their body, and use conventional methods such as sports to keep them in shape. That kind of position/attitude is probably owed to my left-wing political background.
However, things have started to change. Like in many other cases, there is sort-of an ambivalence inside myself. The one side wants to see the person in question as a human being, from a humanist / human rights / all-people-are-equal point of view. This side wants to warn about risks of cosmetic surgery, about potential complications, the follow-up procedures for replacement implants every couple of years, etc.
On the other hand there is my pervert side. This side thinks: Well, how much more extreme can you go with the concept of "suffering for beauty"? There you have a woman who is willing to have quite extensive surgery, probably every couple of years just in order to look better. Actually even more specifically: To look more sexy. To look more attractive for you.
Looking at it from this side is actually a quite big turn-on. I would still never require anyone to do something like this for me. I'm too responsible for doing things like this. It's a decision with a lot of consequences... but if a woman was willing to do it in order to look more sexy [at least partially] for me, then I could call myself a lucky bastard!
It is also one step further in the direction of fetishizing the actual body. Not only wearing fetish gear like high heels, corsets, latex clothes, etc. to change the body appearance from the outside, but actually changing the very shape of the body itself from the inside.
Also, I perversely like the psychological point of the woman in question objectifying her own body, perceiving it as a surface that she can shape by whatever means available. To learn and experience that her body can become supernatural, more than 'just' nature, ...