Addicted to Online Games

I was just on the phone with my cousin who is 15 years old. He just called in to ask if he can drink the Coke in the refrigerator and if he can play the computer this afternoon. I immediately answered 'yes' regarding the Coke but hesitated if I should allow him to play the computer. You see, this boy's very addicted to online games that he even goes out of his way to know about call of duty cheats. He really should be banned from playing the computer on weekdays but I still have to learn to put my foot forward to take him out from his addiction.