I'm not ready to fall in love right now

It was a great day, as far as 2nd grade goes, and there wasn't any major drama as of 2:00pm. 45 minutes to go. A girl student came up to me and showed me a note that was left on her desk. It read: I love you, from guess who. I read the note and gave it back to her and said, "Ohh, hot stuff." She's the kind of girl that is tough and can take my joking so I was feeling good about making that kind of comment. Well, little did I know that she wasn't really that okay about it. She came back to me about 10 minutes later and said, "Can I talk to you in private." Of course. We moved the conversation into the hall and she said, "I'm not ready to fall in love right now." It was all I could do without busting out laughing. I had to bite my tongue from laughing. I suspected a boy and asked him in the hall. He came out and said he wasn't the culprit and pointed fingers at another person, a girl. I quickly pulled that girl out in the hall and we chatted. I asked her why she would do that and she thought it would be funny. She then proceeded to cover her face in shame and started to cry. I felt awful. I reminded her to "do work in class and not write notes." They hugged and the girl who got the note said it was okay. They were friends again, actually, friends forever. 2nd grade friends forever.