How do people feel about this situation?

I met a guy recently in a non poker setting. We became friendly and realised we both play so started travelling to some lie tournaments together. When in casinos he will happily play games like roulette and slot machines and it is not uncommon to see him lose £100+ ($200) in a night.

Last week I played him heads up cash poker for the 1st time. I took around $200 from him. I was clearly the far better player.

He wants to play again and I feel this could become a very regular thing. What should I do? I think he's a degenerate gambler. Is it ethical for me to consistently take money from a "friend"? If he is only going to gamble it away in one way or another is it ethical to turn it down and give it to the casino?

I feel unsure how to handle this situation. Any advice/anecdotes?