One morning in Air Temple island. Aang wakes up and goes to the kitchen to see Katara making breakfast for all 1000 air acolytes (for some reason, actually no reason, is no one around to help them - unlike in the fire nation palace, where there is equally as many around as in air temple island, it's just in that case for some reason katara would actually have let them help with chores)
"good morning sweetie", Aang said.
Aang tries to kiss Katara on the cheek, and inside her is an uncomfortable feeling she can't describe. She feels violated. Like she'd already woken Aang up with sex, water bending that boi dry like an apple squeezed for apple juice, but this... Ew. Maybe after all she is just the type to not really be in contact with her own feelings and body and boundaries, despite all the evidence that says otherwise.
"Aang, sweetie. I want a divorce" Katara said.
Aang is hurt! Katara is HIS wife. "Why sweetie?" After all he even has a tattoo on his ass that says "#property of Katara" in the same color as his arrows.
"Sweetie, I know we are happy together, it's just... You don't like seaprunes, and it makes me uncomfortable, like you don't respect me or my culture. Because this 1 dish that I ate one time really defines my personality and belonging. Please eat the seaprunes or I'm leaving you".
Aang ate the seaprunes, accepting the sacrifices a man must make to become a feminist king like Zuko.