(fallen london stamps by as I've implied in the past on my sideblog, Lucent is some flavor of aroace - he loves people a lot, but not romantically, and though he's comfortable with sex, he neither experiences sexual attraction nor has an active libido.
I'm not totally sure what Savoulain's deal is, but his and Lucent's relationship definitely falls outside of the realm of a "typical" one. they rarely kiss or have sex. they sleep in different beds, in different rooms, in part because of each other's late-night research habits. they're more likely to spend their "us time" reading in the same room than cuddling. but they love each other a great deal and call each other partner, and the second person to wake up each morning wakes up to breakfast already made and a lively conversation about what they were each reading last night.
their connection is very much an intellectual one. not at the expense of intimacy and emotional connection - rather, it's fundamental to these things. their relationship might seem cold and detached to the outside eye, but it is anything but. it is sincere, passionate, and mutually supportive, and they are both very content with this arrangement.