On That Note...

Male student 18 years old turns to me in class the other day, whispers in my ear (audibly enough so the whole class could hear)..."Teacher, I need to toilet."  (What did I just teach them?)   The student then proceeded with "Do you have paper?"  I'm right in the middle of my lesson here, for crying out loud.  I scrambled in vain for some tissue. Since the whole class was in earshot, another one of the students thrust some tissue at him.  "Xie xie," he said as he started to leave the classroom.  'Wo you la duzi.'  Gross.  This would qualify as TMI--too much information.  Aiyo, what kind of classroom culture have I created where everyone is free to discuss their 'business?'