From my own personal experience I interpret Halsin as placing value on infatuation, but doesn't want to devote time into developing long lasting love. He specifically says he wants Tav to visit, not stay. I think this is very intentionally done, so there is not created expectations of a longlasting and maintained relationship, which is what he makes clear from the beginning.

Example of a polycule and love: Moving between two households, where each partner lives and divioding time and nurturing those relationships.

Long distance relationship: Keeping in touch regularly to develop and maintain the relationship, and then visit for periods of time to develop that love and intimacy further

Long distance physical enjoyment: Not actually putting effort into developing and progressing the attachment beyond the infatuation stage. Keeping the feelings attached to the infatuation stage and to the physical enjoyment of it, until the infatuation stage has run its course, and both parties move on

Halsin is in the last catagory, as he sets very clear boundaries by saying it's not a relationship, he does whatever his instincts wants him to do, and keeps those boundaries in place by leaving without Tav, specifically calling it a visit, and refering to the physical aspects as the main focus throughout the conversation. While there is some debate on if this is in character for act 1 and 2 Halsin, this is entirely in keeping with act 3 Halsin. He has relationship aversion and as such will responsibly make certain that there are no expectations set for it being anything else.

Halsin is very infatuated with Tav, but he makes it very clear throughout act 3 that he does not wish to but in the effort and commitment it takes for it to evolve into what is usually associated with longlasting love.

This entirely in keeping with his relationship aversion, and if people wish for this to remain a part of his character, then him leaving at the end is what is natural for this character.

I just wish people would stop calling him polyamorous, because placing that label on him does make him seem very manipulative and cruel - and I don't believe that was the intention.

Halsin is a casual infatuation romance, that will likely never be maintained because of the firm boundaries he is setting for it.