¡Te vieron la cara!
caption 65, Provócame > Pilot > Part 17
A literal translation of Te vieron la cara would seem to mean "They saw your face." However, there is an expression in many Latin American countries that goes me/te/se/nos vieron la cara de idiota, which translates literally to something like "they saw my/your/his/her/our face as the face of an idiot" but which is best taken as "They took me/you/him/her for a fool." The ending de idiota is often dropped and merely implied, so when Ana declares ¡Te vieron la cara! she means "They took you for a fool!" (By the way, while this expression is found from Mexico City to Buenos Aires, you are not bound to hear it in Spain.)
Depending on the context of the situation, the phrase can also mean they took you for something else besides a fool. For example, if you are charged a hefty sum for a street taco in downtown Tijuana, you might suspect "They took me for a tourist," Me vieron la cara de turista.