Sadly we have so broadly defined rape these days that it has lost its meaning as a crime of violence.
Further. I agree with @Tainari88 that most men cannot conceive of the impact of rape on a woman. Men have a completely different launching point in any discussion of sex, and the notion of sexual violence to a man has a completely different meaning.
But taking the OP's question at face value, there is real danger at being quick to define any actions as forcible rape. (IMO the only thing that should be called rape.)
A prostitute creates a relationship with a customer that is usually pretty ill defined. It begins at a dangerous place and it usually involves a man who is at least somewhat off psychologically. In the US it begins with a woman who is contriving to commit a crime and looking for a man who is interested in committing a crime.
My default position is that whenever a woman or a man says stop then stop it ought to be. That said, there is some responsibility on the part of both of them to not hazard themselves to go in harms way.
As a practical matter it would be difficult to get a conviction of rape once money has changed hands unless the evidence of violence was indisputable. An equally practical consideration for every man to consider is that every time he engages in sex with another person he leaves himself at least partially exposed to blackmail or even worse charges of assault or rape.
I believe that false rape charges are more common that reported but I still believe that they are very rare. Nevertheless, when a person decides to break the law with another lawbreaker he/she is on very uncertain ground from the outset.
God is a comedian playing to an audience that is afraid to laugh.