When both Parties agree upon a role play situation in which one will try to force coitus with the other person. The rapist will try engage in copulation whilst the rapee must defend against the rape .The rape will end once fornication has begun or the rapist gives up and is unable to to force sex.
boyfriend: I could have sex with you anytime I wanted even if you didn't want to
Boyfriend: wanna bet?
Girlfriend: I accept your challenge for consensual rape