Most Helpful Guy
You are already hurting him by saying no all the time. You need to be honest, it is the best way. You are young, if you learn this now, you will get a huge head start in life. Just be honest with him and apologize for playing games. It may suck, but such is life. It is better to admit the complexity and full spectrum of human experience, than trying to shelter yourself in false ideals.
Most Helpful Girl
If you don't like him then you don't like him, you can't make yourself like him. Tell him and be honest about how you truly feel about him. The more you wait and wait the more he may feel like you are leading him or whatever. Honesty is the best policy. I couldn't be with someone that I didn't like anymore, it just would feel weird and awkward.