Exactly like that! Seeing anyone you know with the cringey shit you wrote in your youth, let alone a family member, is enough to wipe all rational thoughts from your mind.
And an addition to that scenario for even more shame, since Yayoi looks so much like the Aoi, and also has a not entirely dissimilar name, it’s entirely possible that Dad based Aoi on her mum. Pretty good chance that they could’ve gone to the same school, after all, so if Dad does turn out to be the author, it might just be based on their highschool life. Or even worse, his cringey daydreams of what their highschool life could be if they were a couple even though they weren’t one yet.