wait...
Uh I guess it's okay since he said he loved her before he came to that realisation? But why is it more compelling now when you remember she was a little girl when you last met?
I mean, if it were me and I met a girl I liked, then I found out she was a kid when I was in highschool, I definitely would have had an aversion to pursuing to date her.
Well, MC did nothing wrong since it's all legal now, I just don't consider any of this a normal thought process when remembering she was a kid you met years ago.
Thinking about it now nvm, that's just me nitpicking the scenario, technically there's nothing wrong, it just felt a bit rushed to fall into love with someone he met as a child.