@Arendsii In chinese, a person's last name is in the front and their first name is in the back. Assuming his name is Zhan Xi, Xi is his first name and Zhan is his last name. And I'm assuming its similar to japanese where you call someone by their last name formally, and you call them by their first name when you are close to them, normally what lovers or very very intimate friends do. So I'm assuming that's why they got embarrased then lmao
Sorry if it's not correct T^T