Fang Chi didn't want to look behind him, not because he was scared but because he didn't want to create any sort of trouble in the store. His fiancée had brought him with every intention of enjoying a day out with him and Fang Chi too wanted the very same, there was no point in getting upset because of some unwanted people. Thus, he didn't want to acknowledge much less greet anyone who would ruin his rare day out with his fiancée.
The mers behind him frowned not liking the lack of reaction that Fang Chi was showing him. When they were kids, they would often bully Fang Chi together, in fact, they treated him as their servant and Fang Chi would always act like one, so why was he acting like this?
