Contrary to popular belief, Deidara, in fact, did not usually enjoy arguing. Combat was one thing - he could show off as much as he wanted to; he could unleash an onslaught of bombs that, once detonated, would turn into destructive explosions that he classified as "art". When he fought, he could create as much art as the amount of clay in his pouches allowed. The often large-scale blasts never ceased to ignite a sense of pride within him, as he had created such a work of beauty. He could take all his anger out on his opponent, and most of the time, with it would come a sense of accomplishment as his enemy was taken down. That was something he didn't gain from a measly verbal spat.
With arguments, his anger always built up, and he felt the need to let it out in some way, usually in the form of blasting the other person to bits. Yet even Deidara knew he couldn't always do that. Although the terrorist had plenty of self-confidence, he was far from being considered a fool. He knew there were fights he was certain to lose, and thus, better to not start one at all, else he taste the bitter embarrassment of defeat. Although, even then, there were times where he couldn't hold himself back as he dove head-first into a battle, ignoring the small part in the back of his mind telling him it was a hopeless feat. He desperately wished to prove that part wrong, to prove his opponent wrong, to somehow overthrow someone stronger than him so he could feel that overwhelming sense of victory. However, as hard as he tried, he never could, always coming out of the battle the loser, which never failed to further increase his anger and frustration. That was why he hated starting arguments with those he couldn't win against.
One of such people was Sasori - his cocky self-absorbed partner-in-crime. With light brown eyes that stared at him with what seemed like disdain and scorn, Deidara felt the need to push himself to be noticed by the child-like redhead.
Sasori and Deidara had been partners for years, and somewhere along the way, Deidara had reluctantly come to the conclusion that the thin line between love and hate had indeed been crossed. He was, dare he admit it, in love with the poison expert that was his partner.
He respected him, that much was blatantly clear considering he regarded the elder as his master - his "Danna". And although the two had conflicting views on art, Deidara couldn't deny that Sasori's puppets had an air of refined quality to them. The craftsmanship, the genius layout of the design, the countless hours of uninterrupted work the redhead had put into them - it would be a lie to say Deidara was never impressed.
So why then would the blond go in search of an argument with him - someone he knew he couldn't win against, someone he respected despite the harsh insults directed towards the superior?
The answer was simple, really. It was because he admired the other that he quarreled with him. Deidara was well aware that Sasori harbored no romantic feelings towards him - that such "useless emotions" didn't exist within the wooden confinements of the puppet's heart. And so, he had chosen to go with the next best thing.
When the redhead got worked up, he spoke passionately, the feelings he claimed to be rid of rising and enforcing every word, lacing each insult with raw emotion. His seemingly dead eyes developed a spark to them, a determination to prove to the blond that his art was the superior of the two.
But what he loved the most was that he always managed to acquire the shorter male's undivided attention. The Apocalypse could be going on for all he cared, but when the puppet master was enraged, his sole focus was always on him.
That was why Deidara loved arguing with his partner. He knew his feelings of affection would never be returned. But to be able to cause emotions Sasori proclaimed as nonexistent to emerge, to be the only thing on his Danna's mind - even if only for a brief period of time - that was all he needed. That was more than enough to make him happy.