It was something that was bound to happen…
Happy was perched on the head of Natsu, during a break in their missions. Lunch was being served and everyone was pigging out after what was a grueling, but fruitful mission, where a village was saved and lives of hundreds were spared. During many missions, the lives of the group were risked in ways that were never thought imaginable, and it had dawned on Happy in the last few missions that at any point, his companion could be hurt, or even killed.
Happy had always gone on missions with Natsu without a second thought, it was something that was expected of him, and something that he loved doing, because he loved Natsu, no matter what happened between the two of them. Sure they could and would get into fights, and not talk to each other for days at a time, but something would always bring them back together. Fights were a part of a friendship, and both of them grew up learning that. They didn't have anyone to teach them that, and they didn't have anyone teaching them the details about life and growing up. Master wasn't the best at that, and didn't even begin to try to teach them. The older magicians around Fairy tail had done a sort of help by committee, and it had worked to moderate success. They had grown up together, through the good times and the bad, and it was times like these that Happy would reflect on the past, the present, and the future.
Happy knew that he wasn't taken for granted, sure he wasn't the most powerful being on the face of the planet, fighting was not Happy's forte, in any sense of the imagination, but Natsu would always come back to him in the end, for advice, for friendship, and for companionship. Happy wasn't just a tag along, which could have been the common thought among many in Fairy Tail, but he knew it not to be true. He knew he was a valued buddy, if at least to Natsu, and that's all that Happy needed.
Sometimes in the past Happy would question whether Natsu really valued him. When they first got into fights, he didn't know what would happen next. He most certainly didn't want to be abandoned, and that was his worst fear, that no one would be there for him. Especially when Natsu didn't apologize or wouldn't talk to him for days at a time, Happy would freak out, dreading what would happen next.
However, Natsu would always come back, and their friendship would be even stronger.
It also helped that Happy was loved by the rest of Fairy Tail almost as much. It really was a good place for him to be in. Happy didn't always like being the center of attention, but he did like attention all the same, and no one was well more liked or thought of when it came to Happy, you could ask anyone in Fairy Tail, and everyone was in agreement that Happy was the perfect companion to Natsu.
Happy knew that he couldn't provide Natsu with some things in life, a fighting partner, a human companion, or a love interest, but he did know that he could provide Natsu with everything else Natsu could ask for, and that was all that mattered to Happy. Happy would sacrifice himself in a heartbeat for Natsu if he knew that Natsu would be happy, and that Natsu would do the same. It was that bond that would never be broken, and keep them fighting together for years to come.
It was that moment when Lucy noticed that Happy was staring into space, and knocked him out of his daydreaming.
"Everything alright Happy?" She asked. She couldn't have possibly known what was going through Happy's head, but his expression did look worried and troubled at times, and she wanted to make sure Happy was ok.
Happy broke out of his stupor and nodded. "Of course! Aye!" And at that, swooped down and stole some of Lucy's food, much to the dismay of Lucy, and the laughter of everyone else.