It's only 9 chapters yet and the story will probably have 60+ chapters so of course that dynamic can change naturally when he's older. It better that the author isn't rushing it and taking the time to explore their relationship as it will inevitably change later, rather than father and son I get more of an older brother vibes tbh.
I read till ch13 and I'm happy that Changdeok still doesn't see as anything more than a kid he lives with otherwise I would be uncomfortable too, so yeah brace yourself for a long slowburn lol

i’m not sure how i feel about this anymore. i’m pretty sure the seme is probably 18 but everyone around them sees the uke as the parental guardian of him and even then where the story is going rn it feels like that’s where the uke is mentally set too. i understand the seme is younger which isn’t new to me but how the story is going they feel more like father and son than potential love interest. idk does that make sense? i rlly like the story and artstyle its js now its giving a family duo than a relationship duo