I’m not sure which other case you are referring to, but if the woman had consetual sex with four men, she cannot come back and cry rape after satisfying herself very thoroughly with the performance of four young men. Nope, that dog don’t hunt. They were all adults.
However, in the case of Polanski, the mother, and a 13 year old child, yes, I agree. Both adults were guilty of crimes against the child.
My argument in the former case was simple: many young women just give up and give in to sex when pressured, even when they do not really want to have intercourse.
The alternative, to say no and risk physical harm, even death, is frankly not much of a choice.
To prove rape when the victim is unharmed is difficult, if not impossible.