You only know that you're in a relationship after you 've subdued the netherbrain.
No, that’s just one of the later ways you can know. It’s not the only indication. If you go to the dryad at the circus in Act 3, you’ll get to do the Love Test with her and if you get all the answers right, she can claim that you’re the first to know her heart. That’s already an indication of her being in a relationship with you as she would just outright reject you if you’re not romancing her.
The main issue here is her romance dialogue tree is
allegedly bugged. This is what's been confusing everyone.
