Getting serious
Over time, the two decided to take things to the next level and became girlfriend and boyfriend. This was a big step up for Katie who before this, had never really been in a serious relationship before. This entire thing was new territory that she was unfamiliar with. It made her a bit nervous.
For John, he had a few girlfriends in the past and knew what he was looking for. Katie seemed to check all the boxes, he was really excited to see where this relationship would go. But on some level, John was very blinded by his attraction towards Katie to see some things that he should have noticed earlier.