Karas sneaks to the library every night. And one of his visits they are rubbing dicks etc. Kara’s returns to his room knowing he can’t be seen. So he asks the guards can you see me. The one guard says yes and dies. And the other one says no and lives. I think the butler goes into their sex room and says it smells like semen and sweat. And they blame karas lustful cravings on the black potion and start giving sex education to Abel and karas separately. They don’t get intimate again until after the main story is finished in the forest.

They removed the dark, explicit scenes from the original novel in the manhwa, so yeah, they're definitely going to stick with shounen ai.