I would go to an attorney. I think a jury would be hard-pressed to believe that a younger professional woman would make sexual advances at a degenerate 70 year old mail room clerk. There has to be a motive for cause. And what would be your motive for doing that? Nothing. Now, if It was your boss claiming these things it might be a little harder to disprove if he could claim you're trying to climb the corporate ladder via sexual advances. The one challenge you will have is why you didn't report it sooner.