Rape...fantasies?

So I was reading Dan Savage's advice column, and recently a self-professed feminist man was asking about enacting a rape fantasy with his feminist girlfriend.

I don't understand this idea of "rape fantasies." It seems sort of like an oxymoron - a situation in which one consents to have their consent removed. Rape is sex (of any kind) without consent. And in the case of a "rape fantasy," people talk this over with their partner(s) beforehand? (Also, as a side note: what kind of feminist are you who would continue to perpetuate this culture of disrespect toward women?!)

It's a very tiny little bit like asking someone to "act surprised" after they already know what the surprise is.

Oftentimes I've heard the idea of "rape fantasies" being nested in the BDSM category. I'm not really sure why this is the case, except for our society's convolution of rape and violence (though this is certainly not the case for all rapes, probably not even the majority).

On the other hand, my first response is to associate "rape fantasies" with the "rape culture" in our society, not BDSM or other deviant sex acts. (Here's a great post on Rape Culture 101, for those unfamiliar with this term. Check it out!) To me, it signifies a misunderstanding of rape and an insensitivity to the experience of rape (to the experience of having one's consent ignored, disregarded, and/or forcefully prevented).

"Rape culture is pervasive narratives about rape that exist despite evidence to the contrary. Rape culture is pervasive imagery of stranger rape, even though women are three times more likely to be raped by someone they know than a stranger, and nine times more likely to be raped in their home, the home of someone they know, or anywhere else than being raped on the street, making what is commonly referred to as "date rape" by far the most prevalent type of rape."

So I'm pretty sure my negative reaction to this idea of "rape fantasies" doesn't come from a prejudice against deviant sex acts, but rather my understanding of it as a logical flaw. Oh and that it is insensitive to the experience of rape, yeah.

What do you think?