quedar como Cagancho en Almagro

It refers to Joaquín Rodríguez Ortega, nicknamed Cagancho, a famous bullfighter in the 1920s, who, in Almagro, Ciudad Real, had one bullfight of such poor quality that the public threw things onto the bullpen and he had to be escorted out under police escort.

quedar como Cagancho en Almagro (first-person singular present quedo como Cagancho en Almagro, first-person singular preterite quedé como Cagancho en Almagro, past participle quedado como Cagancho en Almagro)

1. (idiomatic) to make a show of oneself