I actually had no idea how Wyll ended up in my camp. I don't remember seeing him before that party. I didn't realize he was a potential companion before. So I didn't expect him to be jealous because I chose Astarion or to complain about why I didn't take him to fight the goblins. It was so weird.
I guess they want all the options to be available to you. While it was nice that I managed to seduce Astarion even though he didn't like my decisions, it doesn't make a lot of sense and shouldn't be that easy.
Is there a way to see the attitude you have with your companions like in Divinity? I'm just guessing. Maybe I did something right by him.