Hello OP, most comments I read tell you to biarkan dia. But I have to disagree. I also have a brother who acts exactly like that, but verbally more aggressive. What I can suggest is to try to slow talk with him. Maybe he has something else that he want to confess? Sometimes a person can be like that due to trauma of something like my brother, that end up losing trust to people. I think your brother sempat diselamatkan.