The highlight and embarrassment of my day

Today was a long, mellow, school day until I walked into my last class which was Medical Terminology. I was doing the student thing, talking notes, listening to the lecture when my eye started to wander. From the corner of my eye I saw someone falling asleep. I love when people fall asleep so I kept my attention on the sleeping girl in the front row. For the entire lecture this girl was going in and out of consciousness. At times she was so funny that I had to look away so that I could contain my laughter because I knew at some point I would just burst out. I tried my hardest to pay attention to the teacher but I kept getting caught off guard to the girl in the front row who's head kept bobbing up and down. So finally, just when I thought I could stand it, I took one more look at her. This time she had her arms folded and her head was now leaning back until she realized and she quickly tilted her head up, her eyes widened, she put her arms out in front of her, and did a little "oh!". My friend and I were the only ones to notice it and since I had contained my laughter the entire class, I couldn't keep it in anymore. I started busting out laughing and soon the attention was on me instead of the girl falling asleep on the first row. My teacher paused, looked at me, and I just couldn't contain my laughter so I said "Sorry!" then I left the room. When I composed myself, I went back into class. Right when I sat down my friend next to me went "Dude, did you know that the teacher was talking about the male reproductive system when you left? I bet everybody thought you were laughing at that!" I could feel myself turning bright red. I bet my teacher thought I was so immature that I had to leave when they started talking about the male reproductive system! Overall it was my highlight and embarrassment of the day but I have to admit that a little laughter did my heart some good.