Ask him what he would like to do, or come up with an idea together. You could also set aside time during the week to do something you both enjoy.
[header] How to get your little brother to stop bugging you [title] Set aside sibling time. [step] If your brother is always pestering you when you are hanging out with your friends or chillin' in your room, try scheduling a special time to do something with him. [substeps] You could plan a specific time each week to do something fun with your brother, such as saturday afternoon when you have free time.