What he has done is already sexual harrassment. I know that in these times, a job is valuable. You can handle this without getting the boss involved(which would be fun) or you can just go straight to the boss. This guy has p*ssed you off and invalidated your right to be a woman. So, you get creative. The next time you see he's got his eye on you and starts talking nasty, just pass gass or something, and say something like, "That's what I think of your offer." Or, write him a note that says, "If you say those thingsto me again, I'm going to the Boss." With folks like him, often the threat of being outted shuts them up.