I'm torn on it, I think he overreacts but I also understand it. For me, in that situation, I'd like to think I'd be more along the lines of right, sit down, cause what the fuck is going on.
From MC's perspective, he's 18, so far his relationship history is:
a girl who abandoned him (in his mind), and is living a new life, happy with a new boyfriend (again in his mind)
A girl who he had a massive crush on, turns out she likes him too, but she reveals she has a partner, but is still willing to (attempt to) cook him a meal and fuck him
A girl who took him when he needed help, only to get him tazed, then makeout with him, then tell him she doesn't even like boys normally, and is also willing to fuck him, and makes it clear that she's not only doing it for the scavenger hunt, but because she wants to do it.
He then finds out that two of those three girls have been together this entire time. Add in the fact that he is 18, everyone is emotional as fuck at 18, has had no mother figure in his life that he can ask stuff about girls to, and at this point, his only other friend is one of the girl's brother, who at this point has shown that he has the emotional maturity of a 12 year old who has just discovered internet porn.
I don't blame him for having enough, Maya lied to him time and time again because she is emotionally reserved (Which is justified, revealing secrets with trauma associated to a guy you've known for a few days isn't a good idea), Josy was honest about her relationship status but still willingly cheated with MC.
I will agree though, he is a fucking fanny
