really 50/50 on this cuz for one, i'm a sucker for found family tropes. two, age gaps in fiction are fun to explore. i guess it IS weird when duke basically watched alois grow up since he was 10, and they end up together in the end. it's better to think the duke only developed actual romantic feelings just recently, when alois is already a rational adult and alois himself is making moves on him. them being attached to each other for the same reason that they're basically each other's reason to live is nice, but that's just my take.