Kristen Stewart and Charlize Theron stopped by the Spanish show El Hormiguero during their trip to the country yesterday. The Snow White and the Huntsman costars were up for a variety of fun tasks including a science experiment that required them to wear eye protection and gloves. Their time in Spain wasn't all goofy though, since Kristen and Charlize dressed up for a more serious appearance in Madrid. Kristen's time in front of the cameras will continue when she arrives at the Cannes Film Festival to promote On the Road soon. The festival is already underway and there have been plenty of stars hitting the glamorous red carpet, including Eva Longoria, Diane Kruger, and Marion Cotillard.