hmmm I don't know what to think. It does seem confusing. You can always try option 3 and talk to ur crush about bullying in general since you don't know for sure if he did or not. This can give you a feel of what is going on. He might open up and talk about his thoughts on the subject. Basically test the waters and try to figure what really is happening. If by chance he is really bullying then you can try to draw him into talking about what is going on with him and his sudden change in behavior.
I think learning the reason for his acyions is most important. Maybe he himself is being bullied and is using this other kid as a sort of scape-goat to push his aggression on (???) If you feel like there is nothing you can do yourself, you may want to check if your school has an annonomus bully reporting system you can use. (I know the teens a tutor have a system on their high school's website.)
That seems like a really confusing issue. I think you should talk to him. Don't ACCUSE him, or be judgementatal, but just ask him WHY he is acting that way. "I noticed you've been really mean to ____. It seems weird because you've always been nice around me. Is there a reason you don't like ____?" If he has a reason, you can work from there, but if he doesn't, you can mention you think it's silly for him to waste his time being mean when he could spend his energy on other things.
