His pov is actually shown in the novel but I'm pretty sure it's in the side stories. Rest assured, he wasn't waiting for mc to come of age or anything predatory, it was more like a love at first sight after meeting in the airport and ml was pretty surprised that mc looked so beautiful, pretty sure he had a sense of crisis during the side stories actually
No cause ur so right, I actually expected the manhwa to be kind of tame like the novel since it was mostly the mc being flustered and imagining lewd stuff and iirc it wasn't THAT detailed like the manhwa panels, its js like "he imagined it and he turns red"
Extra: this is SPOILERS but what I'm waiting for is when the arc of ML chases MC comes

The art is so pretty but this whole chapter was a little uncomfortable to read. It feels so abrupt. The ml went from rejecting to having this sexual desire for the mc and then taking advantage of him when he’s drunk. I love sly characters but I wish we see more of his perspective or see why he is suddenly so sexually attracted to him now. Otherwise it feels so predatory considering ml knowing him since he was a baby. Or maybe he was really waiting for the mc to turn of age but still… it doesn’t feel like they have any chemistry so far and it is only lust with ml taking advantage of the mc’s feelings and naivety to satisfy it.