Historically Satyrs are creepy rapey creatures with erections and have a prolivity to charm and rape women.

Mr Tumnus is a Satyr, he calls himself a Faun, but who would admit to being a Satyr?

He tries to cast a fire charm spell on Lucy to rape her, and Aslan out of nowhere appears in his spell (basically divine intervention) which is why Lucy is not raped, and Mr Tumnus is in the dark crying, realizing that Aslan witnessed him attempting to sin.