Im scared he will go too far and i wont be able to stop him.?

I have been talking to this guy, and we have been like full on flirting with each other. To let all you know he isn't a virgin, he hasn't been one since middle school. But i still am. And i know that there will come a time where i wont be, and we have talked about this with each other. its just, i don't want to come off as a tramp. and im scared if he tries something with me, i wont be able to stop. because i might be ashamed of what i had done. or just because i don't want to be a slut.lol any suggestions on how to keep it slow but still get him excited?