You shouldn't talk behind your friends backs.
Amy was hanging out with her friend Carla at the park.
Amy wanted to talk to Carla.
Amy started talking to Carla about the birds they saw in the park.
Amy started talking to Carla about one of their other friends.
Amy learned more about some of the birds that Carla knew about.
Amy's friend found out that she was gossiping and stopped talking to her.