Go to a crisis center they always have rape crisis fliers and brochures on display for anyone to just come in and pick. (they know how hard it is for some to come right out and say can I have some info or I was abused or Im not sure if I am) Those brochures and fliers explains what is and isnt considered sexual abuse. then leave them out on a stand or table. the fact that something new is sitting around will get him to look at it and read it. If he asks why you have it you can say nothing or say its for school, your doctor was handing them out to all the clients whatever you are comfortable with. Then if he starts in tell him "no" and when he starts again say - "no means no or it is sexual abuse, molestation/ rape (which ever term defines what he is trying to do) back off, You have the right to say no and so do I an right now I am saying no" and if you have to hand him the brochure in the process.

You are not his object for his gratification - he has 2 hands and access to a free restroom for that. You are a human being and he should be respecting you as one.

Bottom line NO means No or it is against the law.