I think the best thing to do since no one has said anything about it, is to pretend it doesn't exist, be super professional in all your dealings with him, and never be alone together--esp. outside of work.
i agree with Music on this one. if you have been watching Game of thrones it would be as if Tywin Lannister fell in love.
Forgive my forward opinions, but it seems clear to me that you are intrigued and flattered by the attention of this older, very powerful gentleman's attention. Who wouldn't be? You are excited and mesmerized by what may happen next. I don't mean to be cruel, but the possiblities are that many of your peers will catch on and talk (even if becomes only a fleeting flirtation, people are observant). Do you reallly want all those whispers behind your back? Alternatively, if you have a full blown affair with this man, what are the chances he will leave his wife and family for you? What are the chances if you become sexually involved with him that you will come out of it all unscathed? My humble suggestion is this: maintain your integrity. Stay lovely and strong and enticingly unavailable.