As I'm extremely loud about- I am asexual. I don't experience sexual attraction and, beyond that- I don't want sex, I don't have sex, I don't particularly want to hear if anyone else has sex but I accept that they do. So it might be a bit strange that I support the pro-sex movement, seeing as, by all rights, you'd think I'd be happy if everyone were ashamed of their sexuality and never talked about it, right? Wrong.
The current view of sex in relation to gender is that wermen always want sex and women never do (but should have it anyways), although we've managed to move onto a more progressive place where women are allowed to always want sex, too. This is actually extremely damaging to all asexual. Why? Because asexual women (female assumed, assigned, or anything else) who buy into the idea that women don't want sex can fall into the idea that, if they want a relationship, it's perfectly natural to have sex you don't want just to keep your partner happy. Asexual wermen (male assumed, assigned, or anything else) and everyone else who assumes "everyone wants sex" think they must be broken, and end up trying a ton of things, reasoning "I'll want sex as soon as I [meet the right person/try the right position/get married/have kids]".
But it doesn't help- and eventually having sex you don't want drags on you. It can make you feel like you're broken for not wanting it, resent your partner for asking for it, and it just ends badly, particularly if you've gotten past "I'll want sex as soon as I [get married/have kids]"- which is something I don't wish on anyone. (but, sadly, isn't terribly uncommon- it's similar to LGBT people saying "I'll beat this [desire for the same sex/feelings of having a different gender] if I just push harder to be a normal person and have normal sex and normal marriages and normal kids" and ending up in a terribly painful situation when it doesn't work.)
Why does this happen? Because people aren't allowed to be asexual (or gay, or bi, or trans) and are told that feeling like that is wrong and you can be fixed with [expensive medical treatment that could do all sorts of damage] or [sex you don't really want]. And also because people aren't allowed to talk about their feelings related to this unless they're perceived as "normal". People dance around sex with nudge-nudge wink-winks and set up a high-pressure environment where people feel like they can't openly talk about how they feel about sex.
In relationships, people often go based on the ill-defined relationship model of "unspoken agreements". What counts as cheating in a sexual relationship? What acts does a person agree to when they agree to sex? What pacing (when do you have your first date, first kiss, fooling around, sex, etc) is "acceptable"? At what point are you exclusive? What should you do when you aren't comfortable with something your partner wants? And early in a relationship, when people are most nervous about keeping a good impression and caught up in the wonderful feelings of NRE, it can be difficult to be comfortable talking about all these things that society tells us we don't need to talk about because "Well, you know." (read: "No one actually knows, but it makes us uncomfortable to admit this and a large amount of society is based on these meaningless boundaries so shut up and be normal") And after that wonderful NRE wears off, you've already settled into a "comfortable" pattern that makes your partner happy and can be just as difficult to bring up the problems you're having because you settled into it, too.
People can find ways to work with being in an asexual/sexual relationship, compromises that allow both to get what they need (even if not always what they want), but it's better to start it early- before the baggage of feeling betrayed, used, hurt, rejected, and all of the other problems both sides can feel. But with the way relationships work now, the invisibility of asexuals, that rarely happens. (it's becoming more common as more asexual area aware and accept themselves and can work out what they want, are willing to do, and can't do)
A pro-sex model of sexuality that puts emphasis on the fact that there's nothing wrong with wanting or not wanting sex, that tries to make people comfortable with whatever they do or don't want to do in the bedroom and that consenting to one thing doesn't mean consenting to something else (sadly, a pretty big issue in a/s relationships), can help to limit this. And, in general, it's just a good idea. Finding a way that people can talk about their interests and desires in a low-pressure, low-judgement environment won't remove all problems- but having a chance to talk about things like that can make people think about things they never thought of before. And isn't that just a better situation? Aren't things more enjoyable with less pressure or stress, when your partner knows what you want and you know what they want and you can just enjoy without having to worry about whether your doing it wrong?
So, yeah, while I may get a bit squicked out hearing about sex- I still think it needs to come up. People need to be free to say "I enjoy this, I'm willing to do this, this makes me feel loved" and to also say "I don't enjoy this, I'm unwilling to do this, this makes me feel used". All people.