This was how it begin

As Twilight and her friends were going on a mission, Spike came and was trying to tag along, Twilight told him he needs to stay put at home cause it’s too dangerous and that he is forbidden from ever coming along with them and he’s only to stay home, at that moment it turned into a nasty argument between them as Twilight said he’s too young and shouldn’t be put in harm’s way and that she’s trying to protect him, and Spike said he can take care of himself and he’s always been there to lend a helping hand, then Twilight regrettably called Spike a Nuisance and a weakling who always needs to be saved and that it jeopardize their mission, Spike was hurt by that but he was even more hurt when the others agree with Twilight that he shouldn’t tag along with them anymore and they didn’t defend him. Twilight and the others walked away after she told Spike they will talk when she gets back leaving him by himself to be sad and angry.