Let me do some spoilers further-
Soon Tae will quit (basically fleeing from the organisation with a false identity) UNHRDO after being frustrated internally and Illay will have to suffer tremendous mental anxiety, he will try to search Tae with every possible clue. From this stage onwards we will realise how much Illay is obsessed with Tae. He would even jeopardize his job security over finding Tae which will ultimately lead to sexual assault towards Tae and he will push Tae towards subjugation of his absurd demands during sexual Intercourse. Apart from forced sexual advances towards Tae, he was precisely raped thrice. Illay's greatest demands were always forced on Tae during sexual Intercourse, once was when he demanded Tae would not meet Shinru and the other will be when Illay would demands Tae's owernership to be exclusively owned by him. He asks Tae to say him that Jeong Tae-ui only belongs to Illay Reigrow (This is the way of proposal and commitment between the two). "You are mine Tae", "This body belongs to me" are some phrases Illay constantly will be saying later in order to assert his presence in Tae's life. He will even be branded as a terrorist and fired from his splendid job, when we will try to rescue Tae after he would be kidnapped by the Arab Royalty (Rahman- the romantic interest of Jae, Tae's hyung). Illay will just grow more and more obsessed with Tae in the future. He would ultimately turn Tae into a perfect bottom as his sexual partner by the end of the story.
