Read the novel it will explain way more better also yes xinlu talks about the first love with that idea but yuri didn’t have any first love either romantically or sexually even yuri himself said he didn’t know he was into men after sleeping with xinlu cuz he thought he was straight and only love to sleep with women ! So what yuri meant was deferent he just thought about that night and didn’t tell xinlu any more details cuz he know xinlu hates the man who saved him
So it was all misunderstanding yuri himself said in the novel his first love was just platonic cuz he loves the sea with beautiful things

Why is he saying his first love was 12 and he was 25.. can they stop