I can't believe people are suggesting to give up part of your internet connection to an ex friend you haven't bothered with in a long time.
I don't particuarly care for their circumstances either, they're not a close or even a friend at all, the OP said an old friend.
Even going halfs is out of the question, because if he downloads non stop who are you to tell him to stop? He would be paying.
Let's not even get into the legal issues should he download movies, games and music illegally, as I'm sure OP you know you'll be the one responsible as it's registered to you.
edit: the person in question has his mums sky number to stream tv? It gets better. Does he even pay rent or is it that his brothers place?
Not to mention OP will have to buy a QoS router just to share it.
AND, let's remind the community that lowrider doesn't have a great income himself and has had numerous problems in his last place, the last thing he (or I) would want is crap like this.
Good post and sums up exactly what I was about to type, so thanks for saving me that effort! I also don't understand the logic of even considering this as a possibility.