Natsu
"Igneel, what's a soulmate?" A small Natsu asked his father, when they laid around the fire after a long day of training. Igneel looked at his little human, "It's someone who you want in your life forever." He answered. "Will I have someone like that?" Wide eyes looked up to his father. "Someday son, someday you will." They fell asleep.
Gray
"Momma? What's a soulmate?" A little raven haired boy ran up to his momma and papa that was on the couch. His mother, Mika, picked him up and placed him on her lap. Silver watched the two interact with a fond smile. "Well, a soulmate is when you feel butterflies in your tummy whenever you see them. You want them to be your friend and then something more once you've grown older, and don't want them to leave." The little boy looked at his mom and father with big, black eyes, "Would I find someone that makes me feel the butterflies in my tummy?" Mika smiled at her son, "Of course dear. Everyone finds someone once they're older." Gray smiled, then he yawned. Bedtime for the little one. She chuckled at her small son. Then got up and kissed her husband's cheek and tucked Gray in his bed.
Years later when they join the guild
"Oh yeah! Fight me!" Natsu yelled at Elfman. They both got up to fight. Crash. Erza bumped their heads together. "Enough!" Gray watched from the table he was at, looking at Natsu, he felt fluttering in his stomach. He blushed and looked away when Natsu caught his eye. He was a blubbering mess when Mira started teasing him. Is this what mother was talking about that night? Gray shook his head and went back to his drink.
Natsu stared at him from afar after being separated from Elfman. He blushed when he saw Gray looking at him fighting. His stomach was bursting with flutters. He went back to challenging people to fight.
Time skip
They were helping Galuna island get back to normal. Trying to get rid of the moon drip. Gray was out of magic power. "I can still fight!" He argued with Natsu. "No! You can't. You need rest!" Gray stepped forward, "but..." "No!" Natsu interrupted. "I don't want you to hurt yourself any further." "Why?" Gray called back, "Why won't you let me help you!?" "Because I love you!" Both stopped and looked at each other. "W-what?" Gray sputtered. "I love you, Gray. You're my soulmate, and I don't like it when your hurt anymore than you are now let alone dead. I just want to take care of you and be in your life forever. I need you, Gray" Natsu looked down. Gray was stunned. "Soulmate?" He was silent. Then he ran to Natsu and crushed him into a hug. Natsu immediately responded. "Yeah, soulmate." Gray smiled, "I've found you." Tears were spilling. "And I you." They merged into one.
The end
Author's note Gratsu and Natray fluff!😊 Enjoy!😊