It can be seen from your answer that you should like this coach, not his major. As for him, he is angry because it is not standard to have class with you. But from a fitness instructor's point of view, it is normal for members to behave irregularly. So it can be concluded that your coach's life is unhappy. It just broke out with you in class. If you really like this coach and feel better recently, it is enough to care about him next class. Or simply change coaches.