Sorry this is happening. You need to get the principal involved in this on Monday and request not to be his partner with anything. Never let him come to your house or be alone with him. If he does get near you, then you need to kick him where it hurts. You should also block him from contacting you online and don't talk to him anymore at school. Take a self defense class or enroll in karate lessons. Don't wait or else this will continue.