Three dollars and some change

Interesting how it's the power equal as opposed to the place in Anita's life that's the threat to Jean-Claude.

This hints at the idea that Jean-Claude is older than he's letting on, more likely High Medieval than Renaissance. In the medieval mindset, there was the Great Chain of Being, in which everyone and everything had his/her/its place, both in this world and the other worlds, the homes of demons, angels and other spirits. People on the higher spots of the chain weren't jealous of those lower down, and everyone on the chain owed fealty to whoever was above them on it, all the way up to God Himself.

Nathaniel's position is akin to that of the traditional role of a wife, the supportive, receptive, subordinate helpmeet. (Richard himself has commented on how Nathaniel acts like he's Anita's wife.) As such, JC probably sees him not so much as an independent being, but as an accesory of Anita's, subordinate to her. (And this pisses off Richard to no end, because, with his more modern mindset, he sees this as Nathaniel being a cunning little sneaky snot, stooping to conquer.)