Just wanted to play with how all three's dynamic works.
Lord Nacre Cookie broke off from his original house to form his own by age 14, and with his scary intellect and connections grew rapidly.
His house is the leading power of armed marine forces and even a merchant trade armada, dwarfing his original house's significantly and therefore has a lot of respect and influence. His family even holding him to be a standard of what their future heir Lord Oyster is supposed to be.
Certain that he will do great things like his brother, their "hope" as it were, to help put their house in the limelight and maybe be a candidate for a seat at the Convocation of Elders.
And that stress tends to.... Get to him... Especially when faced with his intimidating brother...