Any form of obsession is not a great thing, even if it represents passion for significant others. You might feel a strong feeling towards anything and that's normal, but letting it run you isn't ideal. It will cloud judgements. I'm not saying he is entirely wrong about his obsession, maybe it's the only way he knows to show affection. His intentions are far more important that his obsession. Try to understand from what intentions his obsession originates from and why/how those intentions are dictating his obsession, I'm sure it'll make the decision that comes afterward easier.
And please do the understanding part gently. See his problem (even if it seems irreversible) as if it's going to be fixed. It'll be preferable if you helped him figure this out, he'll come to his senses eventually. Heck you being by his side through this might be a stepping stone for strengthening your relationship.
May 20, 2020