I think a formative part of incest au Jon coming to terms with his sexuality should be an all-out obsession with his dad. Over time he gets better and better at hiding it until he’s convinced he’s over it and normal now but there’s a good few years where he’s constantly thinking about and obsessing over and creeping on Elias. And it’s incredibly formative to him.
His kinks and fetishes and understanding of sex and relationships is like. Hugely informed by the fact that he spent several years wanting his dad to bend him over and fuck him soso bad. And maybe nobody would ever guess on their own but if anyone who knew him ever found out it would genuinely explain So Much for them.
I think Jon should work his ass off to get into Oxford in the vain hopes that being away from Elias for a prolonged period of time will help him get over his deeply inappropriate feelings and prevent him from doing things like “snoop through Elias’ collection of sex toys” or “creep into his room to spy on him while he’s asleep” or “hide in his wardrobe to watch him.” And it sort of does work! The feelings cool, he gets a romantic partner who he doesn’t really care for but who at least isn’t his dad, a few months of distraction and he thinks he’s finally feeling settled enough that he can spend winter break back home <3
And of course there’s this odd tension between them winding higher and higher and higher and there’s something possessive in Elias’ eyes and all those feelings are bubbling up brighter and sharper than ever and Elias is kissing him and Jon is kissing back and grinding against his thigh and fumbling to unbuckle his belt and-
Well. It’s going to be a very interesting break for Jon <3