"you can't do that, I'm the Fire Lord !" "watch me !"
The Fire Lord’s family was on holiday at Ember Island. Sokka insisted on going because "nothing can make a person relax better than sunbathing with the sound of the ocean and a coconut filled with the quenchiest Cactus juice," which earned a disapproving look from Zuko, who does not want his husband, Cactus Juice, and their children in the same place at the same time (which is fair when you think about it).
So there they were, on a beach, sunbathing. Zuko had to admit, these kind of holidays were really relaxing. He could feel the sun unwinding all the knots in his shoulders and neck. His mind was the equivalent of a calm pond, only the heat of the sun and the sounds of his family could approach the pond and not trouble it ...until Izumi metaphorically jumped into the pond (and physically onto her dad).
The Fire Lord was startled by this sudden attack but calmed down when he heard the familiar ringing of his daughter's laughter. But then she yelled "Dada ! I've got Daddy ! Put him in the water ! Put him in the water !"
Zuko tried his best to wrangle himself out of his daughter's grip (without hurting her of course), but she had help from her brother Druk.
With this turn of events, Zuko knew he was doomed. How do you escape your children when one is a ferocious and strong being and the other a dragon ?
He could hear Sokka running towards them. "You can let go kids, I'll handle him !" Sokka said.
"Are you sure Dada? Druk and I can help ! We're a good team!" Izumi proposed and Druk nodded along while puffing out some smoke from his snout.
Zuko took advantage of this moment to try and escape his impending doom. He was nearly there, freedom was waiting for him !
...until he felt his dear husband's hands on his ankles.
"No you won't escape like that !" the dear but evil, husband asserted with a grin.
"Please Sokka, you don't want to do that," the poor Fire Lord pleaded, but it fell on deaf ears. In an instant Sokka lifted him off the ground and ran to the ocean. Zuko tried in vain to escape again, shouting "you can't do that, I'm the Fire Lord !" only to be answered with a "watch me !"
And then, without any warning, he was unceremoniously dumped into the water. Sokka was laughing loudly and the kids were joining him. Hearing all of them laughing and being so happy, careless and safe filled him with love. If being dumped into water by his husband with the help of their children was what made them smile, then Zuko would do it again and again without any doubt.