niittinaatti
Surprising that Oberon cares enough about his kids to care about their gender identity.
Oh, he doesn't care about OJ...he cares about his own image and position of power.
You see, Mogdir's high rulers are elected democratically by the citizens every 3 generations. This means once a ruler is elected, their bloodline will rule in a monarchy for 2 more generations before a new election is held. Anyone who is blood-related to a previous ruler is forbidden to run for election, which prevents the same group of elite assholes from holding power for too long.
However, if a ruler does not have blood-related children (or if their children are unviable to rule for whatever reason, such as poor health), this forces an early election.
Traditionally, Mogdiri heirs take the throne well before their parents' deaths. That's because culturally, Mogdiri people hate being ruled by ancient, decrepit leaders, and will violently overthrow infirmed kings and queens who refuse to retire. So, they willingly pass on the crown when they're old and in decline, and their children are in prime health to take their place. The old ruler then enjoys their golden years in elite luxury while their kid does all the hard work running the kingdom.
Oberon doesn't want to see his son experimenting with "alternative" sexual/gender identities because in his eyes, this means OJ is less likely to have biological children. In that case, Oberon's family's power ends with OJ.
Oberon is such a vain, greedy ignoramus that he can't stand the idea of his bloodline only ruling for 2 generations rather than the ideal 3. In Mogdiri culture, this is considered shameful and a bad omen, it reflects poorly on that royal bloodline in the history books. Fauns can live for quite a long time, and Oberon plans to live long enough to see his grandchild plop their ass on his throne one day, thus keeping himself in the realm of elite noble society for as long as possible.
Oberon has 4 children, but OJ is the only one he has faith in to take his throne (Winnie's rebelliousness threatens him, Trista is a homicidal maniac, and Nate has crippling anxiety) so he's putting all his eggs in OJ's basket while praying, "Please don't be gay, please don't be trans, please don't be weird, please don't be mentally ill, please don't embarrass me, please just be a carbon copy of me in every way and make me look good in the history books..."
Then OJ says, "Hey Dad, what does it mean if I feel like a girl sometimes?"