"Doggy," Callista said, her mouth feeling dry. This was still better than studying on a Saturday, she kept telling herself. And a little part of her, deep inside her, was sort of thrilled by this. Krista, a woman, cared about her sex life.

"How often do you masturbate?" Krista asked suddenly. She said it in a whisper, but Callista's first instinct was to look around the library quickly to see if anyone heard. Her cheeks felt hot and her eyes were wide. This was beyond sex; somehow this was worse, "Well?"

"I don't know, like twice a week I guess," Callista said. Callista thought about lying on her stomach on...