Crazy in Love by Dandi Daley MacKall
Mary Jane enters her senior year of high school having just been at a party where she flirted, with reciprocation. The trouble is that Jackson is dating the popular and gorgeous Star.
Her entire girl posse breaks into two factions: those who would like to support her, and those who are definitely upset at the breach. Mary Jane also hears two very distinct voices in her head telling her oppositedirections: Plain Jane, who wants her to be the “good girl” and M.J., the sexy alternative. Mary Jane and her two best friends, now both in college, have taken a vow of chastity before marriage. Her friend Alicia is now having sex with her college boyfriend; Red is not, because her boyfriend believes in God.
No cussing, lots of kissing, off-page sex. Not recommended.