by peabo85
A nice short chapter, focusing on Sam's view. I especially liked her thinking about Cal's behavior and her feelings for her sister.. that's probably the one big topic that's still open about this story.
Personally, I think it would do good to the story if you could "spice it up". I'm not particular to BDSM, but I imagine you could try and explore what it means on the mental level, not just the physical - how it feels to submit to the bonds, maybe fighting a creeping feeling of panic as she loses control (what if Cal tries something Sam doesn't want?), or balancing that with whether she trusts her sister. It should be a tug of war between various emotions.
It could also really use a sexual aspect - I know you don't want the sisters to have sex until they're ready, and that's OK, but that doesn't mean they can't have sexual feelings at all. They have young, horny bodies - and with the things they're doing, they would get aroused, and want to seek release one way or another. This could also become a point of drama/conflict in the story, especially for Sam. There's several ways this could go, even without them having sex.
Carol's sudden entrance was a bit surprising, on several levels. I forgot how much she knows about the sisters. But mostly I was surprised the sisters would leave the front door unlocked when doing such things. That's quite careless when you think about it.