Da-som coincidently finds Do-Hoon's old ID on the floor. She later returns it to him asking some questions. Do-Hoon then decides to tell her about his painful past, and so she feels guilty about asking questions and hugs him. MC uses this situation to invoke jealousy into Mrs. Lee Sohee. The latter leaves them all alone for a work meeting & the work mates don't waste any time and they get straight to fucking.
After the modeling shoot was over, Do-hoon and Park Da-som were all over each other in the waiting room at the studio, Ye-eun having been in the room before they got there, hides behind curtains and watches them enjoy a very good shagging with multiple positions.
While still at the business trip, Do-hoon comes over to Dasom's hotel room and have his way with her and she doesn't stop him (because she already fantasized about doing it with him) and also because she initiated it by kissing him in the bathroom in a work dinner.