it seems to me that Josy is very sexually free (or at least a lot more uninhibited than Maya) and this aspect of hers really impressed Maya at the famous summer camp.
so I don't even assume Maya is a lesbian.
then being basically a virgin, it is normal that she is in difficulty with MC, both physical and psychological, because she has to question her sexuality, which is already never easy, but beyond that her sexuality has already cost her the relationship with his father and now MC puts everything in doubt.