While this isn't sexual harassment or a hostile work environment as defined by law, what he's doing is certainly enough to get fired over. If he reports to her, then she has the authority to fire him. However, if her boss says she can't then she can't, and there's really nothing she can do about it.
And certainly there's nothing you can do about it. I recommend you stay out of this, it really isn't any of your business and could get you fired if you start fussing about it.

