I have recently been having these fantasies where the girl is tied down and told that she is going to be made to orgasm. Using an egg vibrator inside her, a magic wand held against the outside and a very powerful stimulator directly against her clit. Only when she has cum, she is not released but made to have orgasms over and over again. Im not sure what would be the best timescale to keep her like this. I think that if you didnt tell her how long that would be a very good mental torture to go with the physical one, just tell her she is going to be kept like this for a very long time!!