I don't see any fear of commitment with him. I think that's a bias from mono people here.

Monogamy is just not for him. That's a very poly story to be honest. A lot of us just find out we fall in love with multiple people, and trying to just be with one doesn't work out. We would feel unhappy.

And it's not about the sex. Halsin wants you to follow your heart. It can be with him, without him, or with him and someone else.

At the same time he's sex positive. Everything is fine as long as all partners consent. He also seems to stay sex positive after he endured things others (like Astarion) would have felt as assault.

It's not shallow just because he's wired differently.