yes and no to a certain child

true

I'm the youngest and it's more the other way around forme

for me they both say yes and no to both of us, but if logic was always like this what would happen if:
Youngest bro: hey mom
Mom: yes sweetie?
Youngest bro: can you allow my older brother to *insert thing that middle and oldest child want to happen/do*
Mom: ...

so its a task for old bro but mom doesnt allow for old bro but always allows young bro so she has to say yes

or the other way around
Oldest bro: hey mom
Mom: yes?
Oldest bro: can you allow my younger brother to *insert thing that younger brother wants to happen/do*
Mom: ...

so its a task for young bro but mom doesnt allow for old bro but always allows young bro so she has to say no