I had my first lucid dream... but it"faded"?

I had my very first lucid dream last night. I will jump right into the part where I first noticed I was just dreaming.

I was standing in the school hallway, a few feet away from the back door of the science lab. I just noticed that I had forgotten my homework, again. (We have homework due first day back from break, and I havent gotten it done yet...) But the I realized that it was a just a dream- I had nothing to worry about. Just like that. I was very excited that I was conscious of the fact that I could do whatever I wanted. I was even more excited that I wasnt waking up, just like every other time.

I looked through the door and saw my boyfriend. He was staring towards the front of the room, just like everyone else, at the teacher, who was talking about something I could not hear. I realized I could kiss him and do everything else as much as I wanted, without getting in trouble. I walked through the door, leaving my books behind.

I walked over, and crawled over his desk and plopped myself into his lap. I put my arms around his neck, and he put his arms around me. It felt so nice... I started peppering his cheek with kisses, and the teacher was STILL talking! I stopped kissing my boyfriend and turned around. By now, another student was talking, and the teacher glanced over at me and gave me a mean look. The teacher wasnt the one we have in real life. I then turned and whispered to my boyfriend, "Do you want to cut class with me?" knowing that we could do this without ACTUALLY getting in trouble.

In my peripheral vision, I could see that his eyes had grown big and he shook his head. Regardless, I then grabbed his hand and pulled it with me through the door. But then he separated himself from me. I then turned around and went back into the classroom, but it was empty.

I spent the rest of my dream running from people, trying to catch me. I was scared to death, but mostly for my boyfriend, because I didn't know where he was. By now, I had long forgotten that I was lucid...

What the heck happened? It was going so well... :(