Wow, what an absolutely gorgeous chapter, I really love the abstract panels!
As for the ending, I think it's Jukyung's mind not letting him go through with it. Deep down he doesn't want to take that kind of risk. Which makes sense, because it seems (at least from my interpretation) that he was an unwelcome surprise that may have forced a marriage between his parents. A marriage which seems not to have been good for either them or Jukyung.
Here's hoping he actually communicates this to Gye and doesn't just leave her hanging with "it isn't working"