by peabo85
Interesting and original.
IMO Sam should be the "normal" one, an average girl who just happens to be the subject of Cal's twisted ways to show her affection. Maybe they both love each other, just in different ways, Sam's being the more common sisterly love, while Cal's love is more of the romantic type.
Maybe as they explore their feelings we can get more intense erotic scenes with actual sex, rather than just bondage and teasing.
Keep at it!