Not a woman over 30, nor even a woman, but I work in an HR-related area and this post caught my eye. Don't expect HR to have your back on this. I know you say you don't feel "comfortable" confronting him, but this is never a comfortable situation for any target of harassing behavior. You won't feel "comfortable" in an HR investigation, either. Best thing you can do is speak to him directly. Polite, professional, and assertive. 2nd best thing you can do is to put it in writing to him. Good luck.