Combustive Properties by The Cerebral Hentai
Series: Sailor Moon
Sex factor: some
Kink factor: questionable consensuality
This looks like an interesting story. Unfortunately only the first chapter of it is available. Rei finds herself acting oddly, following impulses she doesn't quite understand, which lead her into bed with Jedite and to seducing another girl at school. And, through the guilt, wondering if it's really herself that's making her do these things.