How should I approach a friend who thinks constant repentance makes ongoing sin okay?

Hey everyone, I've got a friend who's regularly engaging in haram actions, especially with non-mahrams, and he keeps saying it's fine because he repents right after, since Allah is the Most Merciful. But to me, this feels like taking advantage of forgiveness – like you're just repeating the same mistake. I'm not sure if I'm right or wrong here, so could someone please advise? BarakAllahu feekum.