Disclaimer: I do not own One Piece.
It was early in the morning when Ace came home. Robin dropped him off for Zoro since the man was still taking care of Luffy.
"Zoro! Luffy! I'm home!" Ace shouted as he barged inside and almost forgetting to remove his shoes. Robin grinned and helped untie the shoelaces for Ace was too excited to see Zoro again. When Zoro peered from the doorway, Ace kicked off the shoes and gave the older man a hug.
"Zoro! I missed you!"
"Welcome home Ace."
"Did you miss me Zoro?"
Zoro knelt down and hugged Ace properly, "I did."
Ace pulled out from the embrace but still held his arms around Zoro, "I was gone the whole day but are you okay? Did you keep the doors locked? You didn't invite anyone did you?"
Suddenly, Zoro broke eye contact from Ace, and a faint blush formed across his face. Ace caught it and anger blasted like explosives.
"Ace, calm down. It's just Sabo's dad." Zoro stroked Ace's soft wavy hair to try to alleviate him. His son grew cranky whenever anyone other than him, Luffy, or Robin was near Zoro.
"Sa-That pervert came here when I'm not home?" Sabo's dad was with Zoro without his protection? The man could do anything! He might have hurt Zoro!
"A-Ace," Zoro pleaded and held Ace, "he just came to make dinner for Luffy. There are still leftovers. Do you want to try some?"
Ace really wanted to say no, but his stomach grumbled at the right timing. Zoro smiled and took Ace's hand, "Can you wait in Luffy's room while I heat it up?" Ace nodded, collected his bags, and ran to Luffy's room with light strides because he remembered that he found rocks for Luffy. Zoro stood up and grabbed the hems of his shirt. He waited until he heard happy squeals and shouts in the bedroom before facing Robin.
He raised his hand toward the direction of the bedroom, so Robin silently nodded and walked. Zoro walked beside her.
"Um...thanks for picking up Ace."
"You're welcome." Robin giggled, "Be careful Zoro."
"He's quite serious."
Zoro scratched his hair, "But he's still a kid...and look at me, we're years apart."
"Age doesn't matter."
Zoro chuckled, but didn't say anything more. Ace was growing up so fast. Was this how a parent felt when they watched their child grow up? He and Ace weren't connected in any sort of gene or blood whatsoever, yet he was feeling that same bond. There was a sense of happiness and loneliness in Zoro's heart. Soon, Ace would grow up and leave his nest to become an adult. Maybe he would visit from time to time. Maybe he would never return. Zoro hoped that when that time came he would be sane enough to live on his own.
Robin and Zoro entered the room where the two boys were talking amongst each other.
"Look Daddy!" Luffy shouted through mucus clogged coughs, "Ace gave me pretty rocks!"
"Let me see." Zoro sat down so Luffy could hand him pebbles, "They're nice and round."
"I'm going to put them in my treasure box!" Luffy grinned as he pointed to the closet where the box was hidden. Over the years, Luffy collected many pieces of rocks that sparked his interest. Sometimes he picked up bottle caps and coins, or anything shiny.
"The man at the campsite said that rivers make rocks smooth and round." Ace explained. Luffy awed in amazement, so the older brother felt proud for teaching Luffy something new.
"Wow," Zoro smiled and patted Ace's hair, "You're so smart." Ace blushed and pulled up an embarrassing smile.
Robin knelt down but kept a distance between her and Zoro, "Ace, Luffy, I came to tell you something."
"I know what she's going to say!" Luffy chirped excitedly.
Robin smiled because Luffy was right, "You two have been great children, so we're going to give you two a reward."
"A reward? What is it?"
"We're going to take you to the aquarium."
"Yeay!" Luffy shouted out louder than Ace. He was jumping up and down so feverously, Zoro had to hold him down. "When? When? When?"
"We're still thinking, but it will be soon."
"Yeay!" Luffy and Ace cheered again.
"Oh, one more thing," Robin explained slowly, "Sabo and Mr. Black are coming with us."
"What?" Ace was the only one who booed. Zoro and Robin exchanged glances and gave a wan smile. "Why him?"
"Because we promised..." Zoro held Ace's hand, "So be good when he comes with us okay?"
"Oh! Ace! Guess what?" Luffy shouted in glee.
Zoro's eyes widened slightly, and he reached out for Luffy, "Luffy, no-"
"I saw Sabo Daddy kissing Daddy!"
Robin held her mouth and turned to Zoro with a surprised expression. Zoro froze and slowly his face grew red. Ace was the last to react, and he began to tremble like a volcano on a brink of explosion.
"Oh...almost kissing Daddy." Luffy added, a bit of information that came too late.
"What?" Ace shouted, and he grabbed Luffy by the collar, "What else did he do?"
"Ace! That hurts!" Luffy screamed and looked like he was going to cry.
"Ace, stop!" Zoro tried to break the argument, "Sanji didn't kiss me! H-He almost did, but I stopped him!"
"I don't want him to come with us! Zoro, please don't let him!"
"But I promised Sanji, and he's going to help us find the right date too."
"No!" Ace began to tear up and started to sob. Luffy suddenly started to cry too because he thought it was an appropriate time to cry. The two children crawled up to Zoro and cried into his lap. Zoro brushed his hands over his sons' back, and sighed. He glanced at Robin and gave a weak chuckle.
At this moment, Ace vowed that he would not take his eyes off of Zoro and protect him if Sanji attacks him with kisses. Zoro vowed to keep Ace occupied, so that he wouldn't start kicking and punching Sanji when the man was innocent. Luffy vowed to find all of the fishes he wanted to see at the aquarium. Robin sensed that it was going to be an interesting trip.