Responses

Just because he's mentally adult as a kid, doesn't mean he remains mentally 40 years ahead of her. Mental maturity doesn't work like that. Let's just say he grows into his mental age.
Also, don't worry about any romance. Any confession (yes confession!) for our MC happens when they definitely of adult age. But there are romances and marriages for other characters in the series, if you're wondering.
Yo, i'm actually worried if they end up together.... Remember, they met when they were children(physically) while Youngguk's mental age was somewhere in his 40s. During that time, Youngguk kind of felt something (AUGHHHHHHHH FUCK NAHHH), so i'm wondering if they do end up tgt. It'll be fine if Youngguk gained feelings for her at their adult age though, I'm just worried that there'd be a sudden flashback where Youngguk is blushing at her while they're a teen/children (physical age).
PLEASE DO LET ME KNOW, feel free to spoil his romantic interest cus it's an ick for me bwahahahah