nah don't misinterpret. this isn't anything like that, he didn't have any feelings for jaekyoung back then, but he always admired him and thought he was special too. the feelings he expresses for child jaekyoung cannot be compared to any romantic feelings he experiences now or in the future (actually, he doesn't even feel that much for jaekyoung yet. You have to wait for a while before he develops his feelings for jaekyoung).
also, once you get to see jaekyoung's pov, you'll see how VASTLY different their feelings were for each other at the time.
I am going by what the MC said in chapter 18. That when ML paid him a compliment, when he was 12, his heart throbbed and fluttered. If the author didn't want it to be misinterpreted, they should have phrased it differently.
Everytime we go to MC's flashback and he talks about how he had the feels when a 12 year old talked to him and compare that with the current ML and find them similar, dude..that's not cute. At all. Seriously author. Tf?