Why can't the MC also be at fault? He knows Josy is in a relationship, yet he can pursue her. Maya tells him she doesn't want guys to be interested in her, yet he can pursue her. If he does both of those things and gets attached really quickly to both of them, then it's his own fault for not reading the signals.
Contrast this with Sage where the MC can say 'no' to giving her guitar which essentially closes her off for the time being, and then in Ep 5 she ask him why and he explains that it's because of her situation with Chad. He recognises in this scenario that he shouldn't get involved with someone who's in a relationship, yet with both Maya and Josy he's less concerned about that.
This, to me, is more an issue with the way this story has been written than it is with any character flaws inherent withing the characters in question.
I believe she was just on his leg, but even if she did, so what? Have you never been hugged by a female friend and felt your dick press against her? Or what about her tits? Does this touching mean she's leading you on sexually?
Just sounds like typical guy thinking to me; "She just looked at me/touched my shoulder/hand/arm/leg, that must mean she wants to fuck me."