FWIW, from my personal experience with a friend and her 50/50 son, being educated in a private school in Bangkok, the Thai kids and even the Thai teachers to some degree, have a problem with 50/50s and there is a strong tendency to discriminate against them and harass them. Other countries seem to handle this better. Unfortunately, this leads to a lot of hard feelings and embarrassment. Of course, the same can happen anywhere but seems excessive here. He's a top student, which probably aggravates the situation.