Gateway Sector contains roughly a hundred and fifty systems in a fairly empty part of the galaxy. Of those, perhaps a hundred have any value (ie: Mining of airless moons orbiting gas planets.) The only system with any habitable planets is the Gateway System, which in turn contains Gateway Station, an alien relic which can open wormholes to other galaxies, as FTL travel is impossible outside the galaxy. The drives just will not work. Nobody is sure why.
Because Gateway System is pretty much the only civilization in the sector, the captain in command of the station is also the Military Govenor, which, because most of the Sector's population is in Gateway, also puts the job of protecting the sector on said captain's shoulders. It should be an Admiral's job, but the Royal and Imperial Navy is a bit short on Admirals (No such thing as a Commodore in this Navy) at the moment, so it falls to a Captain.
In times of conflict, the captain oversees the Sector defense, the executive officer is in command of the station and the planet, while the second officer leads any field missions involving the Navy forces under the captain's command.
The Empire has just come out of a war with the Feenar, a felinoid race whose civilization is built on honor and a caste system. They're a warrior race, very proud, and a bit touchy.
So when the second officer marries a Feenar female, she suddenly becomes the highest ranking Feenar in the sector. Because Feenar law says that the female controls her husband's house, and the Second officer is the Sector's field commander, Gateway is now Feenar territory.
Or, more simply, the Second officer is the top warrior in defense of the Sector, and Feenar Law does not recognize the military rank off the captain and the exec in this situation.
Am I missing something or does this make sense?