She comes on to you

"So, John," Kristen murmurs, leaning against her door. "I need some help with my Nutrition Homework." She smiles as she licks her lips. "I think I need more protein." You're not quite sure what brought out this behavior--you know that she and her boyfriend had been having problems, but you thought that they'd solved them by now. Obviously not, considering how she was smiling at you now. "Whaddya say, John? My room or yours?"