it's like platonic love... you have to clean up your way of thinking. it's the same as saying your first love is your father, your mother, your brother, your sister, even your pet... you will love them without any bad intentions, right? it's the same as yuri on xinlu's beauty :)) he likes xinlu romantically on the grown up xinlu
no offense, but thats a terrible answer.
psychology, the reason your "first love" could be your father, mother, pet, etc. is because you grew up with them, they bring you comfort, security, etc.
here we have some dude who on first encounter became mesmerized with a little boys beauty as he was drowning and then he looked back at that encounter as his first love.
i hope you understand why i find this writing choice very very very weird.
HuftYuri was not sexually attracted to the child. That’s simply not what his feelings were about, so framing his first love as inherently predatory because of that is a misinterpretation of his character and the context. I gave an analogy like liking an idol because that's what it was like when he liked Xinlu's beauty.
the idea of an adult perceiving a child in any form of 'mesmerizing beauty' is a predatory set up...imagine in real life an adult being like that and talking like that about a child, would you seriously think thats acceptable?
its not mischaracterization, hes not a pedo, but this framing is intentional and the writer could have done it a different way.
spoiler: scroll down if you want to read
Xinlu is an unreliable narrator, he wasnt actually a child during the drowning incident, it was actually a recent even after the main passion story. Xinlu just remembers wrong because of trauma and stuff.

why do they gotta frame it in a way that makes it look like he fell in love with a child, like wtf