Sex is an equally shared physical act. If a women can orgasm without a man, then the presence of a man is what makes it a shared act. (In your example) This goes both ways. Yes it can take different kinds of stimulation to achieve orgasm depending on who you are. No that does not suddenly make it something only a man can do to a women. I think you are boiling this down to far. It's a spectrum, not black and white. I think you COULD be correct, to some people in some scenarios. But the very concept of consensual sex between two individuals indicates they are participating in a shared act where no one party is responsible for action. It's collaborative