Even without any explanation, I feel that the MC's initial feelings for Josy, and even hers for him, are entirely understandable and relatable. Anyone who's ever had a school crush, or a work crush, or a summer crush, should be able to recognise in the MC those same feelings of admiring someone from afar, of being infatuated with someone without really knowing much about them. The physical attraction is there, and you might exchange the odd word or two, and you get a good feeling about them, but neither of you are confident enough to make the first move. That's how I'd say it feels with Josy, that they both have an attraction to each other but are both too timid to make the first move; Josy because she's technically still with Maya, and the MC because he's worried she'll reject him.
Josy does, however, need some more character development because she was largely absent for the first season, and so far in this season she's been something of Maya's wingwoman. She hasn't yet got a chance to really shine as a solo act so hopefully we'll get some much needed one-on-one time with her in Ep 7 (but not at the expnse of Maya being taken away
). Would also be good to get some insight into their (M&J) relationship before this, particularly before they first hooked up, because I've always got the sense that Josy just did what she did on the camping trip for fun and to experiment because her and Maya were friends so she thought nothing of it, but Maya took it very seriously and that Josy somewhat fell into a relationship with Maya that she never intended to have.