The most embarrasing moment

In China, classes of schools and colleges will hold their own new year's parties at the last day of a year. Students celebrates the new year's coming, and it should be enjoyable. Once I was invited to give a performance in another class with my partner. We gave a comic dialogue, and we got a good feedback. When I was tring to get back to my classroom, the monitor of that class stopped me and let me choose one balloon over my head. I selected one, and she broke it. There was a slip of paper which said "be overwhelmed by an unexpected favor". She asked me to behave what a person would be like when he was overwhelmed by an unexpected favor. I had no idea about that and just stood there without doing anything for a few minutes, while the whole class was looking at me. Nobody mediated a dispute, and I felt there was a fire on my face. It was a really hard time for me. Finally, the next performance continued instead of me.