But Joanna did not say "it is necessary to do so with some[one] you are in love with". Here is what Joanna wrote:
=> I think there are two good reasons to have sex with someone: => 1) you love them and are sexually attracted to them or 2) there is => a strong sexual attraction."
Unless we have a very different idea of what "or" means, (2) makes it clear that you are not required to be in love with the person.
In another response you wonder why even sexual attraction is required. Hence Joanna's analogy with eating. People who eat when they are not hungry (generally speaking) do not have a particularly good reason to do so (the analogy could be flawed but for other reasons: perhaps nutritionists recommend that one not wait till hunger to eat). Hence her use of the term "good reasons". Now this leaves it open for you to define what your type of sexual attraction is. It could include "fisting" (the quotes are added not to scare those of you whom seem to find them scary, but just to denote that I am not entirely sure what this term means to you, and therefore in my reproduction of it).
The confusion surrounding films and sex (on which Andie responds with incredulity) is based on your analogising Joanna's view that "sexual attraction is a good reason to have sex" with "sexual attraction is a good reason to go together to the movies". She is quite right (IMO) in pointing out that this is a bizarre (my word) analogy. Andie's response is off target since he reads Joanna to be saying that films are not about sex. Films may be about sex but that has little to do with whether you use sexual attraction as a requirement for choosing whom you go to them with and further whether such requirements are analogous to whom you choose to have sex with. I can offer a different version: being edible is a criteria for choosing what you eat. It would be a bit bizarre to analogise this to saying being edible is a criteria for choosing whom to go to the movies with!
With all that out of the way (at least my way), what of your claim (as I see it) that one should not need sexual attraction in order to have sex. Assuming the obvious, that the original proposition is not tautological, this raises two issues only the second of which is directly relevant to this thread:
The first, to get it also out of the way, is whether one should have sex based [only] on sexual attraction. What of sex with prostitutes where only one of the individuals (or perhaps none!) is sexually attracted? Why not sex as a satisfaction of needs: the prostitute needs some money and the John (Jane?) needs to get off. Is sex a matter of getting off (to use a flippant term; better served by "one individual's sexual satisfaction")? Is masturbation sex? Tricky stuff, at least to me, but fortunately avoidable in the context of this thread, so we can move on to:
The second, is the question of what if any of such criteria (and behaviour) is "scripted" and how that relates to "freedom". In response to the suggestion that particular sexual behaviours (or choices or __insert__ here) are "liberated" (*more* liberated), especially in the sense of liberation as one might see it in a "lefto" way, Joanna has (IMHO) a legitimate position. Here I am examining the two positions in the broadest sense (i.e., not in a narrow sense that practitioners of particular behaviours practice *only* that behaviour, for which case Joanna's point is trivially true) and I read her to be saying this: that any preference important enough of being labelled implies a [at least soft] requirement (in the sense of satisfaction) which in turn implies a limiting criteria, despite the appearance of expanding the domain of activity. To understand this, I can note that "vanilla" (as non-BDSM folks are condescendingly referred to -- more on that in a separate post) sexers do not not call themselves BDSM-sexers because they do not practice BDSM (and hence the condescension is mistaken), but because they do not consider BDSM an identifying/defining factor of their sexual activity. Hence Joanna's point about a script (Joanna makes a stronger point with reference to fetishes and freedom but I will not get into that for I have probably done enough harm already by attempting to speak for her).
It would be disingenuous to not note that, should I be correct above, there could be additional considerations: BDSM-sexers might identify themselves as such only to make explicit the discrimination against such practices. After all, I am sure BDSM-sexers (as noted) do probably practice other forms of sex as well (just as "vanilla"-sexers do).
--ravi