'Some students are absent because they are fat.'

Every class I teach there is usually at least one student missing because they are practicing sport, music or dance. Last Friday though I heard the best reason for some students being absent.
My Thai partner said to me "Some students are absent because they are underground." By underground she meant in the bottom of the building. I asked what they are doing. She explained to me the students are absent because they are doing an activity because they are fat. She continued to say the students will play games and learn how not to be fat.
At the end of class I went to have a look and sure enough all the fat students in the school were grouped together excercising.
It's the sort of bluntness you have to get used to when teaching in Thailand. If you are fat they will tell you, if you smell they will say etc. etc.