
Dang that last chapter was not kind on me. Chang-il really be getting the short straw in all of life's options. I know Yona being all obsessive is not a great look, especially when there's two other crazy obsessive guys (each one worse than the previous) but at least Yona showed some chatacter development in chapter 17 when he finally cracked open the door to realising that Chang-il really isn't enjoying the sex and that he probably put him in the same position in the past.
Similiar to another commenter, many I'll have to sit and wait this one out since it really isn't helping my heart reading this kind of plot and being left on a cliffhanger.

In the present time, he is already mature and knowledgable in those bedroom matters, as for the past time (current arc) he does appear to be immature in knowledge. Spoiler below:
Although they basically have sex, it does seem that Hyo-un is really pushing the matter. I don't think Taehyuk had the power to physically stop the guy
Heck, he still feels everything is wrong. I'll give the guy the benefit of doubt for now. Hyo-un can be pushy imo.

Honestly, the way Hyoun describes pthe past, as well as considering that Hyoun has been defending/benefitting the Taehyuk's cousin, aka the King's descendents (modern Taehyuk is from King's lineage, not old Taehyuk's) I feel like past Taehyuk might run away from Hyoun and get caught by the king who negotiates a deal with the dragon. And then, past Taehyuk either dies or suicides idk and the dragon falls into depression/amnesia because HE was somehow responsible for his death.
This is purely my speculation I haven't read the raws so take it with a grain of salt.

Maybe one day I will understand but somehow it's really hard to follow the plot

I think the translation is a little off, that's why it's hard to understand. Like sometimes i think a sentence has a certain meaning but the translation is just a bit off or taken too literal in word to word translation instead of the actual meaning of what was said, something like that?
The translator does put in decent effort to make the grammar good tho, I gotta give them props for that (glad it's not one of those 'am I having a stroke?' translations we usually see).
If there's an official translation maybe just wait for those to be uploaded. ^^
The cry puddle