What I remember from it is that Casey was raped or almost raped in this story and she stayed at Olivia's afterwards. In one of the chapters they Were talking on the couch and everything was so emotional for Casey and they began making out on the couch and Casey got off while grinding on Olivia's leg and she was so embarrassed but Olivia ensured her that it was fine. The story is an old one. At least 5-6 years old. Don't think I read it on the ralst site, but somewhere else.
If you know of it please let me know, cause I've been thinking about this story for about a year and it's driving me insane that I can't find it!