I remember that it was bl, i don't remember if it was like a manga, manhwa, or novel. But it mightve been a novel? The ML is like some sort of dragon person. I remember the ML broke his horn, and breaking the horn is considered one of the most painful things that can happen to a dragon person. The MC kissed the ML's horn and the ML said that they can't feel their horns. But soon after the ML started blushing to himself because the horn is one of the dragons most sensitive places... thats all I remember
Maybe this http://www.mangago.me/read-manga/tale_of_the_yellow_dragon/?3Uqm ? Not sure tho lmao since I actually didn't read it. Or maybe itt's Fantasy Farm where in the ML doesn't say he's a dragon to MC but still gave his horns to him.
I believe this might have been from King's Game, chapter 83 the mermaid arc -- ML was a water dragon or a dragon of some sort and broke his horn to cause himself pain to try to remember MC.