Be Right Back, Uninstalling

I know this might sound really stupid, but i seriously need your help..

My brother just came back home and he started using Internet like crazy, i know this is normal, but when you live on the countryside, where your max connection is 560kb/s it's a big deal.  He started downloading stuff like a madman and he's currently downloading LoL with all the updates, which will take over 12 hours, using up over half the bandwith.

Luckily he doesn't know a lot about computers, so when he started using a lot i just turned off Wireless from the Router's config from my PC, stopping all his downloads and since i didn't touch the box, nobody suspects, but now he started plugging his notebook via LAN so i can't use that plan.

Is there a way i can lower the max speed that a PC can recieve via the router's menu? Seriously, i would post a pic of Speedtest pic of my current internet speed but the site won't load claiming a network error (because it takes forever to load), and worst of all, Steam won't open.

If there is a solution, help me please :<.

The simple answer is no.

The more elaborate answer is no unless you have a much more expensive than normal home router that would normally be found in a large business that has that sort of feature, or you have a dedicated PC firewall.

Do you also turn off the hot water heater when your brother is in the shower?

I'm not saying he doesn't deserve it, he may be evil. But at parties I like to play the game of "Pick one: Internet or Hot Water?" and the results usually run pretty close. So this is to feed by professional interest. Thanks.