Came up with silly esoteric Vulcan genders for them cus it makes me smile, but they're not set in stone. In Human terms they're both nonbinary, but their relationship would probably be considered heterosexual on Vulcan (again, in human terms.)
They're incredibly stupid, on some levels. But, they take IDIC seriously. They take Vulcan swingers parties seriously. They take their business seriously. Tok used to work as an engineer. Stell was an academic studying the history of Vulcan eroticism and art. Together they invent new sex toys.