Sorry to hear that you quit your job Amy but agree with the others you need to tell the boss.When I was your age and learning to drive my first driving instructor had "wandering hands" I didn't tell anyone but a decision I regret now.It will be very hard, because like you, I just wanted it to go away.
You still need to report the incident/s Amy as he may of done this before or will do it again if he thinks he can get away with it.A simple factual account with dates and times. The boss will have to start to wonder if there is more than one report or will in the future if it happens to another employee.