Honestly it’s hard to blame the boyfriend if he gave up. Every signal from her showed him that she was pushing him away, and he gave her a lot of chances. Every indication was that he really did like her and has been faithful (as far as we can see).
That said, immediately swapping over to his coworker without formally breaking up is just a cowardly way to live. So is not speaking up when he was upset when he couldn’t come over.
Also, why couldn’t they just go to his place instead? Or somewhere else like a hotel? Why is it her place or nothing?
Good for our MC for giving her a hug. It’s kinda awkward, clearly out of his comfort zone, but he did it anyway because that’s what she needed most. He reached out as one human to another and it probably saved her from completely spiralling.
I don’t think he has any romantic interest in her, at least not yet, and respects that she’s in a relationship. I do think that he doe like her boyfriend, or maybe just his handsome “type”… maybe his ex cheated with a guy like that?