The author should do them as switch. It's looks better if the older brother iss the top

The whole point of the story is that the ML self-sacrifices lmao so of course he'd give up his booty (●￣(ｴ)￣●).

If they switch it'd be the same domestic grooming story but because the positions are switched in some ways it's more layered because it's subverted slightly. ┑(￣Д ￣)┍

it's still the same domestic grooming story lmaoo just the groomer take it up the butt this time