The short answer is “Yes.” But there are some important details to consider.
There’s a general distaste for rape fantasy because there is a very reasonable general distaste for rape. Rape is one of the most horrible things that a person can experience, so it’s only natural that there’s a strong social condemnation of not only rape, but of anything that is seen to encourage rape. This is all perfectly reasonable, except that we don’t always agree as a society on what kinds of things–stories in particular–encourage rape.
Rape fantasy as a rule does not, because people in general can tell the difference between fantasy and reality. Also because most rape fantasy stories I’ve seen, read, heard, had, or written, have as a context that the rapist is a Bad Guy, and that rape is a Bad Thing.
When dealing with people who cannot tell the difference between fantasy and reality, almost anything can be used as some sort of justification for almost anything. John Hinckley Jr. used the movie “Taxi Driver” to justify shooting the President of the United States, for example. Mark David Chapman used “The Catcher In The Rye” to justify assassinating John Lennon. Neither of these crimes, nor many like them, were reasonably or logically inspired by the original source material–the crimes were the products of deranged minds, and the source material could have been anything.
On the other hand, the movie “Clockwork Orange” may have inspired several rapes. In one case, a 17 year-old girl was gang-raped by a group of perps who were (as in the film) singing “Singing In The Rain.” I tend to think that that group of perps would have been rapists in any case, and the movie only directed slightly how their crime manifested–they’d have still been rapists, but they might not have been singing rapists. Normal people who watched that film were not inspired to go out and commit crimes based on it. Still, there’s an important difference between this crime and the above crimes by other works: glorification.
The movie “Taxi Driver” doesn’t glorify the main character’s attempted assassination of a politician. The main character is clearly intended to be lonely, pathetic, and misguided. “Taxi Driver” wasn’t filmed in such a way that viewers would or should come out of the theater thinking that the assassination would have been a good deed. “Catcher In The Rye” does not–to the best of my knowledge–even have murder or assassination as a plot point, let alone glorify it in any way.
“Clockwork Orange,” on the other hand… well, the main character is not clearly the villain of the story. He’s charming, charismatic, and sympathetic in places. He’s the kind of character that people might want to identify with on many levels, and the rape scene itself was a mixture that contained more comedy than horror, downplaying the effects of the rape, up-playing the coolness factors of the perpetrator. I don’t think it’s necessarily true that the movie created rapists where none would have otherwise existed, but I do think that it’s treading along an edge that makes me uncomfortable, because rape shouldn’t be glorified.
You may be asking yourself why writing ANY kind of rape fantasy is okay, and the answer is that writing fantasy is by default okay and natural, including fantasies about crime and violence. If reading or watching a story about murder, rape, robbery, theft, and so forth, was truly harmful to society, then every society would be constantly harmed by the vast majority of the stories we tell. But that doesn’t seem to be the case.
We can watch horror movies without committing murder, usually because we know the difference between fantasy and reality, and also because the stories are usually told in such a way that it’s clear who the villains are, and that their deeds are vile. Even in cases where there is some sympathy for the monster/killer/villain, the stories aren’t a glorification of them or their deeds. In cases where they are, those stories are again treading on ground that I’d rather they avoided.
Same with crime stories, for that matter, although for some reason bank robbers, kidnappers, and so forth are much more likely to be glorified than movie monsters/murderers.
The only other times/ways I can think of (other than rape glorification fantasies) where it is NOT okay to write rape fantasy are:
When You Don’t Know You’re Doing It
Unfortunately, many authors–even or especially famous authors–have written rape scenes that are seemingly intended to be something else. One example that comes to mind is the sex scene in Ayn Rand’s novel The Fountainhead, where the protagonist Howard Roark sneaks into Dominique’s bedroom at night, pins her wrists, physically overpowers her in spite of her fighting back, and has rough sex with her. It’s all meant to be okay, because a) Roark could tell just by looking at her that she really wanted him to do it, b) even though she said No, she meant Yes, and he could just tell, c) she enjoyed it, d) she entered into a romantic relationship with him afterward, and e) all the usual things that rapists think or say to justify their actions. As a rape fantasy scene it’s not bad… but it does glorify the act of rape, and justifies it, and the author seems to be oblivious that this wasn’t just rough, hot sex.
There are also countless other novels where the author seems to be trying to write a passionate love scene, but instead depicts a rape, sometimes a quite brutal one. Writers can mistake “lack of consent” for “passion,” but they’re not the same thing. When you write a sex scene, check it for consent. Consent doesn’t have to be verbal; it just has to be clear enough that the characters involved, along with any witnesses, would be able to tell that everybody was having fun. If/When you write a rape scene, make sure that not only do YOU know what you’re writing, but that the reader knows that you know it as well.
When It Comes Without Warning:
The sex (rape) scene in The Fountainhead also kind of comes out of the blue. This is supposed to be a philosophical novel about an architect, not a bodice-ripper. There’s nothing really in the book before that point that indicates to the reader what’s going to happen, and that kind of thing can put a lot of readers off. Especially if the reader has been the victim of sexual violence in the past.
Think of it a bit like killing a dog. It’s not something that you want to spring on readers without warning, if only because you’ll lose a lot of readers that way. If you’re writing rape fantasy, the idea will usually be to arouse your readers. That takes a certain kind of audience, and they usually like to know what they’re getting into. If you write in genres where sexual violence is common enough that it won’t shock your audience, something like Beast Porn, Bodice-Rippers, Splatterpunk, or fantasy BDSM stuff like Rice’s Sleeping Beauty Quartet, then you (and your readers) are probably safe.
If you’re writing conventional Romance, Erotica, realistic BDSM stories, and so forth, then you might consider including a Trigger Warning at the start of the work, or telegraphing to the reader PLENTY of advance warning.