Did she receive any marks that would indicate that you went beyond what she originally expected? If not, I doubt that she could come up with any "evidence" that would support her going beyond an exhibition of regret. While I concur with the concepts already expressed, another one comes to mind. She may be either bipolar or borderline. Or both (a combination that is not common but does happen. I know this from personal experience.) This can help to explain the sudden reversal, especially when combined with latent guilt. Somewhat like "buyers remorse." She may have talked to someone with contrary views concerning such activity who has scared her over "those people" who do "those things." After all, there are crazies out there, therefore anyone who does things a bit beyond the "normal" are dangerous. Either way, she sounds less than stable. After all, no good deed goes unpunished.