All the other ones will eventually reach a key point where you can say you are not interested and they will not pursue it anymore after that. Halsin is the only one that continues to pursue it, in an even more creepy and disturbing manner, after you have made your rejection clear to him (and he has confirmed that he has understood it and that he will respect it).
I didn't really notice that while playing. I guess that's the logical end result of turning a reddit thirst trap meme into a companion.
