Oh wow, I really love this analysis! It seems so obvious once you've stated it yet I totally didn't notice!
No I don't see that happening and not because I ship the two. The indicators are not there we would see the dark obsession. Have you ever been with someone who wants to spend so much time with you? Some people forget that there actual people and couples who just love being around each all the time. So no I don't see his behavior in the same light as jihyun.
Funny thing is, as it’s depicted in this story the initial obsessive thinking and behavior is quite the same. Jihyun’s obsession wasn’t “dark” initially. It took some time for his obsession to turn “dark”.
I already stated that the only difference is puppy boy was honest with his feelings from the beginning and he had Chiwoo’s - for lack of a better word “encouragement” as he wasn’t rejecting him. So I’m saying the relationships started basically the same way but forked along the road - one twisted the relationship the other stuck around enough without turning it “dark” to see a happy ending...
I’m just curious, if what puppy boy is doing might not be a start to something similar to Chiwoo’s past relationship with Jihyun;
Becoming best friends, constantly thinking/obsessing about your best friend, constantly pursuing/pushing for a romantic relationship one-sidedly (at least for now), keeping the best friend to yourself, basically alienating any other potential friendship - spent an entire vacation at his house not giving others a chance to visit, using any opening to try and get physically romantic...
BUT, then again what’s different is pretty obvious - The fact that puppy dog is HONEST about his affection for Chiwoo, and the fact that Chiwoo hasn’t “fully” rejected his advances... So it’s probably heading towards a happy ending between the two characters, as Yaoi’s do quite often... ╮(￣▽￣)╭