Confusion or Disgust?

This past Saturday we had a SALI sports day. We invited all of our students at the language school to come play sports with the teachers and university students from Sociedad San Agustin (Peruvian RUF) and members of our church. For 3 hours we all ran around playing volleyball, soccer, and ultimate frisbee. Being that most Peruvians have never seen a frisbee, we enjoyed teaching them a new game. Despite the sloppiness of our game, everyone had fun. Here's a picture that apparently captured a mid-game moment of either confusion or disgust. I, myself, can't tell what's going on.