I’ve been thinking about this for a while and I have nothing, sorry love 🙁
I was prompted this once and the best I could do was fake dating.
I don’t know how these stack up as possibilities. For canon-ish there’s a visa scam, or an inheritance thing, must be married to inherit. Then there’s canon-ish (not on Earth) of Rush surviving to go to Novus, everyone had to hook up to make kids if they wanted to have a sustainable population.
Or if Rush somehow wound up on an alien planet (not on Destiny) that had arranged marriages, a bit like how Daniel wound up married to Sha’re, now that’s not strictly teacher/student, but maybe he would be revered on this world and be given an apprentice, who he then had to marry.
Then go wild with the AU’s. Rush is a scientist in the past when arranged marriages were a thing, I mean math has been around forever, and he agrees to marry his student Belle for whatever reason you like, avoiding another arranged marriage/her reputation/to keep her in school (perhaps her father wanted to pull her out because it’s not proper for women to be smarter than the men they are supposed to marry).
I mean sure strictly speaking aside from maybe the alien planet stuff, nothing requires Rush specifically, but everything is better with Rush. Maybe the alien world pulls a Firefly (Our Mrs Reynolds) and Rush doesn’t even realize what happened at first. He thought he was agreeing to teach her, not marry her.
I can see Rush agreeing to a wife who was a student because she would be smart, maybe able to help him, or at least know enough to leave him alone to work. He thinks it’s just a beneficial arrangement then bam surprise, he falls in love with her.
Any of that spark anything?