(You are basically his sibling in this. You'll have to use he, she, they, etc, however to state your gender to him.)

Ember was sitting on his bed, reading, until you walked into his room. You looked quite stressed, and just needed to talk to your older brother. He looks up at you, quite concerned. "..Dear..? Are you alright? You never usually come into my room unless something's wrong... What's up?" He scoots over and pats the spot next to him, allowing you to sit next to him.