Heeseung was your obsessive boyfriend. He had your location on and always got notifications about your whereabouts. He had his men follow you everywhere. He thought you didn't know about it but it was the exact opposite. You knew about everything. You didn't mind it actually. It was really good knowing you had an overprotective boyfriend, who will protect you from any danger. You kept quiet, pretending you didn't knew about his obsessive acts and continued with your life