That's really easy. No is absolute the moment it's said. If someone says no when they really mean yes and their potential partner responds in an appropriate way, the nay sayer is going to learn very quickly that they need to revise their approach to getting their sexual needs met. To be quite honest, this reasoning falls in line with the logic rapists prefer to attribute to women without it actually being true. Because you know, who really wants to be a rapist? It's so much easier to spew out that kind of nonsense than to actually see ones self as a monster.I agree that in a society that views women as equals and not mere sexual/reproductive objects or marital possessions, there must be a right to refuse sex no matter their marital status. There are two big problems at work here, however.
1) What does "no" sound like, and when does it become absolute - as we all know, in the traditional female sexual submissive role where the male continues to flirt/goad/pressure, etc. for sex, an initial "no" may well be part of the foreplay, the welcome sexual tension as it were. Some women even feel that they "must" say "no" just so as not to appear too eager for sex, even though that's precisely what they want. There are probably dozens of other variations of this scenario.
Men have been known to level false accusations against women lying about having been raped in numbers exponential to that of women who actually lie. Why is so much less respect given to women who claim to have been raped than victims of other crimes? Why do the police make such little effort for victims of rape when evidence isn't dropped into their lap in a black and blue package? How does any one get caught at any crime that they might commit (especially those that are violent) and why aren't these same methods used on rapists in greater numbers? Investigation isn't limited to dna and witnesses, you know. The only difficulty in incorporating proper criminal investigations into our justice system is in the apathetic and/or hateful dispositions of those who enforce the law. That starts with the police but reaches through the legal system all the way to the jury, past that and into the media.2) How do you prove, legally and criminally, that a "no" (however you are defining it) actually occurred sufficient to know you're doing justice? In the overwhelming majority of "date rape" cases (and this is the most similar genre) it's purely a "he said, she said" scenario with no independent witnesses and no physical evidence. Rape is a HUGELY serious and stigmatizing criminal charge to have leveled against someone, and it even can stain the reputation if the person is later exonerated. Women have also been known to level false charges of abuse against men to better themselves and increase their child custody rights in divorce proceedings - this actually happens a lot more often than people talk about.