Trying To Mediate Troubles Between Zee and Dee

Zee and Dee could not get along for two seconds in class. The teacher was hanging off a cliff by her worn down teeth. I said I would try to figure it out. Zee was super angry with Dee. He could not stop yelling about it. Dee and Zee came into my room together. Dee casually mentioned they are brothers. Zee is angry because ten months ago, his mother sent him away. And she kept Dee. I have a feeling this is not something a school counselor can solve. I asked permission to tell their teacher they are brothers. They were adamantly opposed to this. No idea why But I am keeping my mouth shut, so, I can learn more incase there is a next time.