It's called Quality of Service (if you want to make sure you're ET is fine), check the router's documentation, or install a NetLimiter on your bro's laptop
That's your problem with him... Never used one so I don't know if it stays hidden. You could possibly use tricks used by bad people when sending trojans or viruses to others, but that's your research, not mine.
And if you get a "good" router, it should have settings which will let you do pretty much anything... $.$