this is what i did:

I engaged the creep into conversation via email....he'll slipped about something LAME, but I still maintained my innocence...then he mentioned something naughty so i kept it, printed it out and walked over to him, when no one was around then told him wouldn't it be nice if a lawyer AND his wife saw it.

he stopped after. but you can't go to HR or something cause like i said you'll be black balled in whatever industry cause all those smarmy peeps know each other one way or another.