I think people are looking into the NTR aspect a little too much haha
I think can just be seen as a person who doesn't understand the emotion of love because he lacks empathy and is tying down "what ifs" in his mind to something that doesn't exist.
Like when you overthink something it becomes something you find real or times when you're mad about something so small yet can't let go.
I think this was a natural motion coming from this guy who is on the mild spectrum of aspergers, getting caught up with a feeling he can't brush aside.