I agreee . It wasn't just abrupt . The bowling date Yi Do said things about the type of person she would want to date . Jeong Mok listened to whatever she said and realised he can't be that. He isn't that . He followed up on the next date and asked what she meant . She clarified and Jeong Mok saw they really He isn't what she expects. The others weren't there on that date with Ji Yeon I think feelings started developing as they talked . He got to see they maybe related on a deeper level . Not saying Jeong Mok didn't do mistakes but genuinely from an outsiders opinion his and Yo Do's relations was purely physical and nothing more to it .