Bro, Jacob had the hots for her the minute he saw her. In Zoey's texts, she says Jacob let her in. We see her talking to Jacob on the couch about art and San Diego, he takes her to his room to show off his art, and I'm positive he would've made a move if he wasn't such a pussy. They took a few pictures together, and stayed in contact for weeks. He mistook her compliments to MC for himself and had to awkwardly walk it off. He got super excited when learning she was coming to the BBQ, and of course it all culminated in her asking for MC's blessing.
He never acted like a "normal friend", he wanted to tap our blueberry from the start. He just did that stupid thing where he thinks a friendship will evolve into a relationship because he sees signs where there are none, and thinks that being such a great guy will cause Zoey to realize that Jacob is boyfriend material, if not a potential fuck buddy. And he's so obvious about it, it's actually surprising that MC didn't noti—AHAHHAHAHHAA I can't finish that sentence, Tremolo is blinder than a girl who got cum in her eyes. So is Zoey, blind as fuck to not realize she loves MC and that Jacob was waiting to pounce.
But yeah, Jacob is a snake.