You are really very a tolerant boy as you are bearing misconduct of your brother, even-though you have not given any negative response to him. This marvellous attitude would reward you by Allah (SWT). You ought to keep the same behaviour and don't ever think you can get better results by reacting badly. Try to share your ideas with him, and appreciate his ideas. Try to discuss different topics with him. Exchange gifts with him on different eves. It would lead to a better understanding between both of you.
And even after doing this, your brother's attitude does not improve, try to talk to your parents about the issues. Let them know all about him and seek help.