You get to help and find out and solve problems. But sometimes or often they don't what your help it hurts, but don't take it personal.
sometimes if you tell a friend they will try to help but that might make it worse, share your Peacekeeper problems with the teacher or other adults that you know.
The person might just need some time to cool down, give them some space for a minute or two try to help out with bullying too.
don't be that person eating popcorn watching the show DON'T!!!!! and don't rush in between them like SACRIFICE! you can get hurt ask them for a lunch peace treaty then go tell the nearest adult and tell them what happened i the bully does not say yes go tell an adult that you know.