this sounds a bit immature, somebody paying a person to throw flour at you. There are 2 ways you can solve this, being tougher or seeking school counselor. By being tough, I mean you can try to stand up for yourself by defensing for yourself and your best friend. Don't tell your best friend the stuff you heard, try to convince your best mate that you aren't a 2 face (he/she should know that) but whatever he/she is going to hear from people isn't true. Don't be scared because they are older and taller than you. Start playing tough with them and show them who's the boss and you aren't scared. Tell yourself you can defend for yourself and talk out the stuff you want to tell them to give yourself more confidence. The best thing to do would be to go to a school counselor to get some help. If you let them tease you like that, they are going to keep doing it and if you tell them to stop, they possibly can stop.