1 Corinthians 6:18

AUV(i) 18 Stay away from [any involvement in] sexual immorality. Every sin a person commits is outside [the realm] of his body; but the one who commits sexual immorality sins against his own body. [Note: Possibly this means that sex, because it requires the deepest and most complete commitment of human involvement, becomes a unique sin when its true purpose and expression are violated].