I have the same message for you, but deal with him first before dragging others into it. You need to be strong because horny creeps will be trying to force themselves on you for the rest of your life. This is your first test as a woman, to say NO!
Just tell him, "NO WAY STOP IT OR ELSE:"
I'll tell mom
I'll tell the school principal
I'll call the police
Don't let him intimidate you.