Honestly, there is a probably a manga out there with the EXACT power and relationship dynamics as Carol, Miles and Kamala. Teacher wants to fuck male student, male student is seduced but has a crush on female student, female student admires teacher and has budding feelings for male student.
Big things to consider are:>Are Carol's feelings for Miles genuine, or is she basically just a sexual predator?>How quickly does Miles give in, how much shame does it bring him and conflict with his feelings toward Kamala>How are Kamala's feelings toward Miles developed. Obviously, for dramatic purposes, she'll find out about things AFTER she's grown to like him in return.
Kamala's personality shows that she would stand up to even Carol and fight for what she wants, especially if she feels Carol is simply using Miles sexually. Miles honestly never seemed like that deep a character to me, so he'd be the reader's self insert, lost in the erotic adventure but also wanting to basically be a good person and make the right decision. Really play up the melodrama, and you could market this shit to grils as well as your average horny teen male.