He was just joking about the father thing. But yes, he takes Inseob very seriously as his boyfriend ever since the confession. They never declare it properly but Wooyeon has also been very clear who Inseob his for him. Inseob probably still struggling with the nature of their relationship because of secrecy. In the novel people didn't know who Wooyeon's dating not because he denies it. It's because people never caught it. He went berserk when someone slut shame his partner despite that person was refering to the wrong person. In his mind when people talk about his partner, it will always be Inseob. That's why there was like rumor of him with actress due to his reaction when in fact he was so mad that they indirectly talked shit about Inseob. He's that crazy and obsessed over Inseob
Does wooyeon think he and inseob is kinda dating now that he tried to call mr cha FATHER??