How about I start the download on this game even though but my brother has friends over streaming movies. If I start the download, it will cause their movie to start lagging but I'm sure they'll get over it.
Really, why can't you just wait until they are done watching the movie?
I really want to play my game now.
You paid for the game and want to play it now, which is understandable, but you should be willing to make a compromise for your brother. Starting the download now would be rude because you're going to interrupt their movie but you can make a good compromise with him. Tell him after the first movie end's you'll be starting your download and he can resume movies once the download is finished.
I don't have the time to be reasonable now when I want to play.
Games are fun but they are less fun if you have to stop playing to fight with your brother about his movie lagging. Either wait or compromise so that both of you get what you want.