Inspired by the Studio Choom 'Wonderland' video. In the beginning, Hongjoong is supposed to 'slap' San on his cheek, during which San turns his head to face the camera, following the movement of Hongjoong's hand. However, San is standing a little bit too close this time and Hongjoong miscalculates the distance between them. As a result, his slap actually lands on San's face - which is the start of all the confusing feelings San has to deal with afterwards, such as why there is a part of him practically begging Hongjoong to slap him again.
Luckily, there may be someone within their band who can help explain to him what's going on, because that someone may or may not be experiencing the exact same feelings, but not for the first time...
Cross-posted on AO3