That implies it isn’t around already.

….. Y’know?

The deal was that the twins would each choose which of the remaining two they were in love with, and if they ended up choosing the same person, then that person would have to choose between them (MTV must’ve gotten a lot of complaints from outraged parents, without which I truly believe they would have had the winner walk away with both twins). They both chose Trevor, he chose one of them, the couple lived happily ever after. Try not to faint.

What the heck? These women are sisters. How can one of them possibly be “happily ever after” if she supposedly kept her sister from being with the man she supposedly “loves?” This is the most idiotic bullshit ever. These women are being treated like mannequins–they’re there to look hot, but they don’t have feelings or anything.
Now, of course, I’m guessing that there’s no real “love” going on here anywhere (I’d say this of most reality dating shows). So sure, it’s a sham, but I’m sure you’ve got people believing the premise of the sham all over the place, in which case they must be thinking, “oh, women go stabbing their sisters in the back all the time, and they don’t give a shit.” This really does fuel misogyny.

Oh, and this?
they got Scotty’s mother and aunt, who are Jewish, to do the “Hava Nagila” and to drink Manischevitz body shots from between their breasts (I’m not kidding).
Woo-hoo, exotification and stereotyping of an entire ethnic group! How absolutely lovely.

Sex with twins is more “exciting” than sex with sisters, which is more “exciting” than sex with two unrelated women, because twins are believed to share a closeness unrivaled by other relationships.

I actually think that you’re right, sex with twins is more “exciting” than sex with sisters, but sex with sisters would probably be labeled more obscene. If you have two women that are not identical, but identical enough to be related—and they say as much openly—then the idea that you are wanking to incest is pretty obvious. You can ignore that obviousness with twins, which the culture at large, even outside a sexual context, tends to recognize as two bodies with the same identity. This kind of insensitivity to the individuality of twins is only worsened by the objectification of the male sexual gaze. While sisters are generally considered two separate people related by blood, twins are generally not.

That creates a sort of synergism between the lesbian/threesome taboo and the incest taboo, which makes the fantasy extra hottt.

Well, the reduction of lesbianism to something women do to please men is obviously part and parcel of the twin fantasy. However, I think that it’s more of the novelty of having two identically hot women than the incest that men approve of. Sex is generally contrived as a “the more the better” kind of thing, in which the more women you can have at once, the better. Since twins are two people, you are having a threesome without the pesky problem of having to deal with two dissimilar demands of nonidentical women. It’s basically like finding the perfectly submissive woman to your sexual needs, and then cloning her. You’re not having sex with two different women, you are having sex with two same women. There is also the feeling that the twins will not compete with each other, and that their physical similarity means that you don’t have to spend mental energy on figuring out how to not insinuate that one is more attractive than the other or minimize conflict in what can be a emotional disaster. It’s basically all the fun of a threesome without the effort. Also, remember that misogynists are generally very self-entitled. The fantasy that the universe has conspired to create not one, but two women that perfectly suit his every whim meshes with his ideal perception of how reality ought to provide him with the maximum number of women to consume without requiring him to expend any additional mental effort over that required of a monogamous relationship to please them.

but I think the other part of it is that lesbian sex is often not seen as “real” sex on account of the lack of PIV

This I totally agree with, and didn’t calculate in with how I’m trying to examine this gross phenomena. It also might be the case that it’s not considered real incest if there is a lack of penetration or penis. Whereas, a man having sex with his sister is clearly incest, sisters fooling around together is a lesser incest, and twins an even lesser incest—the last being irrelevant in a calculus of “depravity” to the normally socialized male, the second being obscene but strangely titillating, and the first being totally unacceptable. Although, the most “extreme” forms of incest that feature tacit domination overtones such as that between a son and his mother (supposed to be taken as his transformation from a boy who feels love and admiration of a female figure to a man who feels nothing but animal lust and the need to degrade the woman who formerly had control of him) and that between a father and a daughter (something that really doesn’t need much explanation, owing to the extreme modeling of the patriarchal domain of the father over his daughter and the appeal of the extreme degradation of the woman for an audience). In short, there is a perceived continuum of incest in pornsick minds. The lesser forms of incest are fine to jerk one off too, greater forms are not. However, this line is more likely to be shifted or totally erased the more the sex act conforms to patriarchal norms or features a “give the bitch what she deserves” theme of dominating formerly dominant women, destroying the emotional vulnerability of a normal familial bond, or extending the perceived ownership of the male over the female to the sexual realm.

That was a really gross bout of theorizing there. I feel a need to take a shower.