If you don't tell him this is wrong, he may not have realized it. Think this as a way to help him grow up and be responsible.
All my children pay part of their tuitions. They learn responsibilties, budgeting, and how to efficiently use what they have, much more than what they pay for their tuitions
So it is time for your brother to grow up, and it is time for you to teach him another life lesson.
Don't think it negatively. Take this as an opportunty to help him becoming a better person.
