I wonder if the reason he covered his eyes wasn’t because of his eyes but the mole because it reminded him of his mother. And the picture album he kept looking at was pictures of his mother. This is the only plot twist I’m willing to accept.
Do you want to know why? It's in the novel, you'll have to use a translation app.
https://www.52shuku.net/xiandaidushi/pm/h2Fs.html
I think it's also in the up to date ones here
https://www.mangago.me/read-manga/the_substitute_relationship/











This is too cute!! How dare anyone hate this ugly.. I mean handsome baby haha