Joke
It had all started out rather innocently.
James and Lily had been walking back to the castle from a pretty spectacular day together, just the two of them. Lily's tiny hand was loosely wrapped around James' pinky, swinging them slowly as she skipped along beside him. But then James opened his mouth.
That seemed to be where it went wrong.
You see, James Potter was a jokester. The best of the best. Or... that's what his friends frequently told him.
So by the time Lily Evans had extracted her hand and disappeared to the other side of the road, James had figured out that his friends had either lied to him, or Lily was just over-reacting.
And since his girl had suddenly flounced right back over to resume her earlier position next to him, James figured it was the latter.
OK! Another grandparents-date-inspired story! My grandpa always walked my grandma home from school... because he was (and still is) a gentleman. And he's quite possibly the funniest man on the planet... but Grandma doesn't always get his jokes. So Grandpa told me that almost every time they walked home, she's end up on the other side of the street because she got mad at one of his jokes. But then he said "she'd always come right back to me. And she wouldn't let go of my pinky, either. That's why I had to marry her... she wouldn't let me go." I paraphrased... but that's the gist of it!