Discussion: My boyfriend's roommate has a gambling problem.

He moved in about a month and a half ago, and he is pretty cool. He’s from India, is 20 years old, is super rich and is extremely polite. Over the past week and a half he has spent two nights at the casino, most days there and has lost over 4,000 dollars playing Poker. He recently returned from a 30 hour trip to the casino.
Note that they pay for their rooms, so if he had no money, it would not impact paying the rent. (BTW, this isn’t my issue, simply something I thought was interesting for discussion)
Question up for discussion: What would you do in this situation if you were a roommate to this guy? How would you react, if you reacted at all?