Im playing a trick on my brother any ideas?

Ive put some marbles in his shoes. and i thought about putting sum in his bed but the trouble is he is on his xbox and sitting on his quilt so i thought i could try and get him down stairs for a while then i could sneek in and place then under his duvet. But how can i keep him downstairs for a while. Here are sum things that may help you. There is cake downstairs a tv friends he can play owt with and my grandma. he has been annyoing me all day and he locked me in my room so i want to get him back also if you have any other ideas that i could do that would be helpful. Thanks. x x