Sigh...

She proudly said, "Kan saya dah cakap, dia mesti akan datang cari awak! Tak payah awak susah-susah cari dia, hah!"

So how brilliant you are, you think your subject is very important that you dont allowed a student to leave your class! Hey, I am having chemistry class too! And is true, of course I will search for him if he didnt look for me. Fantastic thought!

However, i would like to say that it is not the matter of whose subject is more important. Is the matter of commitment. It was his promise to me and no doubt, his responsibility towards this organisation as well. So, I really dont think you can interrupt the way we work except it is due to something much more important like exam etc or perhaps we are not allowed to work this way?

If every student thinks like how you think, there will be another person holds extra burden. Have you ever consider that?