Describe symbolism in Aura by Carlos Fuentes

In Chapter Four, Aura and Felipe begin their sexual rendezvous by her washing his feet, while repeatedly looking at the "black Christ" hung on the wall. There is an obvious parallel here with the Gospels, in which Christ washes the feet of his disciples. However, in this case, the significance of the act is inverted. Christ washed his disciple's feet to teach them humility; here, Aura does it to seduce Felipe. The inversion, or perversion, of Christ or his actions is commonly used to depict the action of the devil. The most familiar example is the literally inverted upside-down cross, a well-recognized symbol of the devil.