Responses
No it's just referring to our MC because his son, Hyeol, in the original time-line (or book) grew up to be a yandere top towards Kkotsu, but in this time-line he, as Hyeols father, is getting teased. They just needed to add an "s" top in the title: "The Yandere Top's Father is Being Teased"
The title? WHO IS THE YANDERE TOP FATHER (dont actually tell me)