Most of the Zhongchi fanfics I've read that depict the events leading up to Zhongli giving up his gnosis and the development of his friendship with Childe, portray Childe as being so head over heels for Zhongli that he never once suspects there might be something strange about Zhongli, and while I admit there's something charming about it; since Childe is characterized as being somewhat naive at times, I think it oversimplifies the dynamic between the two of them.
In Childe's voice line about Zhongli, he says that Zhongli seems to be much stronger than he lets on, and he says that in a tone of interest, because Childe admires power and strength, so ofc a consultant as polite, humble and suspicious as Zhongli would catch his attention, as it's a quieter form of strength, very contrasting with his own.
I imagine that Childe was initially very suspicious and apprehensive about Zhongli, after all Childe has the instincts of a soldier, but gradually his interest overcame his suspicions. It went from "he might be dangerous..." to "oh, he might be dangerous~"
Thinking about this, I was writing my fanfic about them, and there's a scene where I tried to emulate the dynamic. Up to that point of the story, Childe was growing more and more suspicious of Zhongli; he had, for example, noticed that Zhongli has a Geo "vision" and had asked if Zhongli knew how to fight, to which the consultant had only replied: "I know just enough to defend myself when necessary." But Childe doesn't buy his humility, and one night, while they are having dinner together, Childe "accidentally" hits a porcelain teacup, but Zhongli catches the cup in mid-air with extremely quick and sharp reflexes. Then they have a silent exchange of glances where Zhongli realizes that Childe did it on purpose, and Childe proves a point. Not that he immediately concludes that Zhongli is a god in disguise, but he is definitely not a mere civilian, since civilians don't have such sharp reflexes while maintaining such a refined posture.
I believe this makes the dynamic less about "Childe didn't suspect anything because he was in love" and more about "Childe DID suspect a lot, but at some point it stopped mattering because he was in love." Arguably, I even suspect that Zhongli being a supposed veteran warrior pretending to be a normal guy who works at a funeral parlor would only make him more attractive in Childe's eyes.
I have a lot of thoughts about them, actually, I think I'll start talking more about it.
