The next morning, Du mian tries to convince her that she's right about her period coming too soon. She's wrong, of course, but she can't stop talking about it. She wants to know why her period doesn't come with Cang-Cang's, and she wants to find out why she hasn't been able to get her period to come with him. She also wants to figure out why he's talking so loudly about how her period is coming at the exact same time as another girl's . He's a liar, she tells him, and he should listen to the scientific evidence. There are some studies that suggest that women who are on their period are more likely to have sex with certain men. One study suggests that sex comes with certain chemicals in women's urine, which makes them more sensitive to the smell of certain men's colognes. The study also suggests that women with periods that are close to the same time have sex more often, and that's why they don't have sex as often as women who aren't close at all. Du-mian is all, "Gee, I know what you're talking about, but I'm not going to listen to you anymore. I'll buy you some water and rub your belly with it." Uh-oh.