Nico clung to Percy, his legs wound tightly around his torso, hardly able to touch each other. His arms were slung around Percy's neck, looking up at the bigger demigod with wide eyes.
"D-Don't let me go!" Nico tried to sound threatening but his voice rose towards the end of the sentence and Percy fought a laugh.
"Nico, we're not even that deep," Percy said slowly lowering himself in the water, and Nico squealed as water over took his chest and he scrabbled at Percy trying to get out of the pool. "Look I'm touching the ground."
He butted Nico's head gently, trying to get him to see that if Nico stood up he would barely be up to his neck.
Nico whimpered and buried his face in Percy's shoulder. Percy laughed and took a few steps back.
"Swear by the River Styx that you won't let me drown!" Nico pulled his head back to look at the son of Poseidon, trying to lock his feet together.
Percy just laughed, bouncing the smaller boy gently, as if soothing a baby.
"Nico, if you drown with a son of Poseidon nearby, you are the most unluckiest person in the world."
Nico just answered with another whimper.