When I started seeing “yes means yes” laws mentioned, it seemed funny to me. Why? Because my interpretation of a law of that name was “if someone says yes to sex, it means yes and you can’t go changing your mind later and accusing them of rape.” Because that would be false, whether you are a mattress dragging stunt hound or merely misguided.
Thus I was greatly surprised that it is affirmative consent. That is, absolutely unambiguous yes required each step of the way or it doesn’t count.
None of which changes the problem of his word versus hers, and his word doesn’t really count unless there is concrete evidence. So it really means you need to get consent on paper and/or tape, or to avoid the whole thing entirely, or to stick to partners who are rational humans.
Which would be the case without a law, these days. Especially on college campuses, where the Constitution need not apply.