as the pendulum swings ...
given that for so long it wasn't rape unless she was battered and broken, there has been a push to realign the thinking and the culture of what is or is not consensual sex.
I have heard it argued that a woman cannot rape a man in the classical vaginal sense as that would involve an erection, which is presumed to mean arousal ... in essence that an erection constitutes consent. Odd. However, I have been told with some authority by those in the field (so to speak) that some female rape victims experience orgasms, and that this is a particularly difficult component of the psychological aspect for the victim to overcome.
The contract violation mentioned earlier in the thread would simply be a civil matter, determining when it transcends into a criminal matter is definitely tricky.
For the time being, many states have swung the pendulum decidedly towards establishing a women's rights on these matters.
Other areas where such confusion may occur include contact sports. Is a hockey player that goes over the top simply violating a rule and get 2 minutes in the box, or did they cross a line in what was originally consensual violence into criminal conduct.
The same question is asked: should the law insert itself into this game?
It seems to me trying to endlessly refine the law is a fools errand. This is what juries are for. Oddly, at least in the US, it seems juries are instructed to not interpret law, but only interpret facts. They are to convict (so the judge says) regardless of whether they think it is an inappropriate unjust conclusion.
It seems to me that rape is a crime, it is up to individuals to decide if they want to make a criminal complaint and for juries to determine whether the crime occurred ... not endlessly clever legislators.
Certainly law must be written, there needs to be something resembling consensus benchmarks and standards, and it would seem a jury should be able to parse whether a failure to immediately pull out as a consequence of a sudden change in mood of the partner is a criminal act or not.