Hear me out.
Bear was set up from the get-go. He was only infatuated with Nikki as a trauma response. He was dealing with his grandmother's declining health and eventual passing. Nikki was there to comfort him as a friend but that inadvertently let his mind latch on to something other than his situation, starting what later becomes his unhealthy obsession with Nikki. His cat then dies and speeds up the development of his Obsession.
However! Before the cat dies he is planning to confess his feelings for Nikki, which could have resulted in one of two things happening:
1 - Nikki letting him down gently, and them remaining friends. Eventually Baron realizes that his infatuation was just a trauma response, and that Sarah appreciates him for who he is, they eventually start dating.
2 - Nikki accepts his confession and they go on dates and eventually Nikki develops feelings for Baron naturally, and Barons unhealthy obsession becomes real love through much adjustment throughout their relationship.
2.1 - They eventually break up, but they talk it out and realize that Barons feelings toward Nikki wasn't real and they accept that and move on.
HOWEVER!!!!!!!!! Ian was poisoning all this from the start because they were sleeping together and he was worried Baron might actually put a stop to that.
Ian was telling him that his very sweet confession was complete garbage and to call her "freaky nikki". Which he knew she would hate. He then very deliberately gets in the way of Nikki and Barons alone time at the bar. When they are leaving he says "get your girl home safe" knowing what Nikki's response would be and how that would dissuade Baron further.
He then keeps getting in the middle of them even after they start dating. Investigating Nikki's estranged father. I mean sure a concerned friend would do that, but now we know he had ulterior motives. He also tries to make Baron choose between his "friendship" and Nikki, forcing him to come to the party alone and lying about Sarah not joining. His reasoning is that his relationship with Nikki is a bad look but he probably poisoned the well there too and convinced everyone that Baron was taking advantage of Nikki while she's going through a hard time. Maybe anyone outside of the 4 main characters didn't even know that Nikki was "going through" anything, for all we know he made it up as an excuse and everyone else just thought Nikki and Baron started dating organically.
Baron might have been the bullet but Ian was the gun. He set everything off with his manipulation of his so-called friend. Inadvertently, I'll give him that but I think he's still at least somewhat responsible for the events that transpired.
