I only started there 4 months ago. Had heard all about it by the end of the first week.
Ran into him maybe twice. Last week he kept randomly turning up in my office, today he came in for a chat for 20 mins 
He’s way way above my pay grade so I can’t really tell him to fuck off. My manager (female) came in after he left and asked what he wanted, I didn’t have anything to say so just said fuck knows he was just chatting. She told me to watch myself with him, not in a horrible way but in an advice kind of way.
I’ve got no interest in shagging a married man, especially not one who’s known as the company slut.
Advice? I’m thinking if he comes in again just monosyllabic answers and staring at my screen, but he’s my bosses boss so also don’t want to be rude