"Maybe this isn't a good idea."

Dray yanked Sol back behind the wagon and glared up at him. "Are you kidding? Firing this thing was your idea in the first place! Besides, it's your brother. If we're hitting anyone, it has to be him." 

- excerpt from "All Washed Up"

Dray and Sol are an explosive disaster waiting to happen. Literally. Both have fire magic and a tendency to cause mischief-- Dray intentionally, Sol because he's not so good at thinking things through. Together they constantly get on Blythe's last nerve, but really this was all her fault. She was the one who didn't want to share a room with either of them and thought it would be a good idea to stick them together as roommates for a while. She thought they both would ignore each other. Dray, with their tendency to keep to themself, wasn't one to reach out to anyone. Sol was always too focused on and enthusiastic about his creations to notice much of anything going on around him. Blythe figured they'd stay out of each other's way and she'd get a few days, possibly even weeks, of quiet where she wouldn't have to deal with the trouble caused by either of them.

Blythe thought wrong. Dray wasn't in the best of health at the time and Sol took it upon himself to be their helper. This annoyed Dray a little at first, mostly because everything Sol does is with a surplus of noise, but Dray found themself enjoying his company. It was nice having someone around who didn't judge Dray for past mistakes and who genuinely wanted to make them smile. A close friendship began to form between them with Sol designing new and interesting performance props for Dray on an almost daily basis, and Dray encouraging Sol more than anyone else had before. Partly this was because Dray liked seeing the mischief Sol could cause with his inventions, but mostly because they liked seeing Sol so happy. When Etri began spending less time performing because his responsibility as Adair's sentinel took up too much of his time, Sol began a new carnival act with Dray involving fire and those aforementioned props.

Theirs was a friendship slow to start and slower to turn romantic. It wasn't until Dray and Sol were forced to spend time apart that they realized how much it meant to have the other around all the time. While they were working on separate undercover tasks in Galanvoth, they discovered a way to use light elementals to record messages for each other. These conversations gradually turned more affectionate and when the two of them met up again, they... well, they didn't get together, not exactly, because both were carrying baggage from past relationships that made admitting their feelings difficult. It took them a while longer to admit how much they cared about each other, but while they never said those words outright, it was clear in their actions. I don't think it takes any of the others by surprise to learn that they're a couple. It's much more likely that their friends were placing bets on when Dray and Sol would finally admit it.