I have stayed indoors for 4 days because I hurt my upper lip, which looked like I used too much lipstick. It wasn't until yesterday that I went out with my roommate for classes. However, after one class was over, I, together with my roommate, decided to escape the history class for different reasons; although the teacher of this class is especially kind to me, and cares if I, as a new comer of this class, can follow the classes and has given me much advice.

Anyway, I have not appeared in his class and hung out with my best friend.
I knew in a corner of our campus, there are several guys playing different instruments, which I have just found one week before because I rushed though them unconsciously. At that moment, I was as shocked as them; I cannot stop however, even though I would have loved to, [because my friends had been waiting for me for about 30 minutes/because I was 30 minutes late meeting my friends]. 

For this reason, I asked my closest friend, together with me, to come there again last night. This night only two guys were playing guitar and singing a song quietly there, then one of these guys started to smoke - which my friend disliked.
So I, as I was there together with my friend, left there again.

Then, a much worse thing was going to happen.

While we returned, I saw the teacher I mentioned above. I tried my best to hide myself but he had already noticed me and smiled, but showed his disappointment in his eyes. And I had to say hello to him by putting up my hand embarrassingly.