Comment by LiLi on A Gangster Became a High Schooler - Chapter 45

it all starts with Sekyung being physically interested in someone he assumes (later knows) is much older. And as how much Sekyung is sexually assaulting Deukpal, Deukpal's response will always be physically defensive, like there's one scene when Sekyung just shoves his tongue in Iheon's mouth and Deukpal just chomps down on the tongue - and treats the bleeding tongue later.

Deukapl sets boundaries and Sekyung voluntarily crosses these boundaries, because he knows that Deukpal would pull him back if he did something really stupid.

Sekyung later has a talk with his father (the one who believes that Sekyung killed that girl when he was 6 years old) and his father demands that he breaks off all contact with Iheon. Sekyung only replies that he knows that his father is a monster, who'd think of killing all kinds of people and that he assumes that Sekyung is the same as him and doesn't want Iheon to find out. But Iheon is the reason that he would never be the same as the dad.

The moment Se-kyung was captivated by that smile, Song Yi-heon's leg went over Se-kyung's shoulder and wrapped around his back. Hooking his hamstring over Se-kyung's shoulder, his calf, which had gone behind his back, pressed firmly against his broad back. Caught off guard, Se-kyung was pulled forward, and his co**, which had been resting at the entrance, dug inside.