Idk. It doesn't make sense to me that SHJ still gets a sense of déjà vu when HYJ already patched up his memories in the aquarium scene (when pre-time-skip SHJ entered HYJ's mana stone). I've read the web novel, so I know they changed the order of the timeline, but I still thought they'd tweak some things in this birthday scene.
Bro I feel like any other yaoi I read would feel vanilla to me now