Yeah that too. but even if you're not interested in Maya so to speak, You should tell you Best Friend, after all it is about his sister. and Yeah if you are interested in Maya..... MC has plenty Time and chance to tell her, not only that , but now even Josy wants to do it.
on the other hand , may be he assume that Maya is at least strong enough to refuse something she don't like, especially after she literally say something like : She does not want to sell her body to complete the Hot's task or something. But even there MC not say a word. I get it , a possibility for a Threesome, is tempting, but still.
and if this gonna be used as an obstacle, as cheap drama between the MC and the girls, that "HE not warned them". I'm gonna be Fucking pissed !!