I can't believe I haven't talked about this yet, but I have a headcannon that Alden had the Vacker Legacy pushed onto him like he does with Fitz but Alden fell in love with Quinlin, and even the "It's not gay if you're cognates" doesn't really work for him because he's a Vacker, but his dad keeps pushing him to date his best friend Della who is secretly dating Quinlins best friend Livvy and the four of them make a deal: Quinlin and Livvy get married, Alden and Della get married and they can all be friends and Della and Alden and Qunlin and Livvy can pretend to be together in public but they can be with their actual partners in secret. Well, Alden and Della keep up the act very well and both of them wanted kids, so they agree to have them together. They realize after having Biana that suddenly the Elvin world is paying attention to their kids and not them, so they decide that when Alvar, Fitz and Biana grow up they'll get divorced and pursue their lovers publicly. So after Sophie and Fitz get married, they're technically a bad match and only the douches really look down on them, but Alden and Della sit Fitz, Biana and Sophie down with Livvy and Quinlin (Fitz insisted Sophie be there because she was part of the family now and deserved to be there) but before Della could explain, Sophie says, "Let me guess," and whips the whole thing out and Alden's like "How didyou know?" and Biana and Fitz are like, "It's pretty obvious, guys." And so anyways, Fitz and Biana completely support it and Della and Alden get divorced and get remarried to Quinlin and Livvy each and they're much happier but they still see each other for breakfast and Alden and Della go back to being just best friends, as do Quinlin and Livvy.