Attention. That was the problem. Steve took on too much of attention from those around him. And he didn't have to do anything to earn it. He just stood there bulky and strong not doing much.
Tony had to admit that some of his moves were smooth like when he break in the armory and got a gun Fury was building before computers got it. It wasn't a genius move but it was effective.
His methods weren't the problem. But attention was. Tony loved attention. Sometimes he thought of himself as an attention whore but that was the only way he knew how to relate to people. When he wasn't working he was prancing around and everyone responded to it with irritation or smile. Most commonly first would go the irritation then the smile with women, and the smile then the irritation with men. Because men would approach him as silly and get mad when they would come in second and women approached him as repulsive just to fall down for his charms. Even Pepper fell down for his charms eventually. It was pity it didn't last really but he was too reckless and childish for her caring persona. He loved her dearly but even for her he couldn't change into someone responsible. Even after it was over between them she was kind enough to let him use her as a shield. And she was a useful shield because other women feared and men respected her. It was useful either way because it relieved him from the part of his role he wasn't enjoying since he was captive in a cave for three months.
It was a strange effect but he didn't like to drag strangers into his home anymore. He lost part of his competitiveness in that field. It got fueled in his work.
Women still gave him enough attention to get by but with Steve he came in short for some reason.
It was probably his father's fault that he had a desire to be approved by him. The all American hero that single-handedly won second world war without anyone knowing it. Humble, brave hero with few words but strong convictions.
By the way Steve responded to an alien threat taking charge effortlessly Tony could see his father wasn't just a delusional fan girl. But that made it worse. Because Steve didn't respond in any way to Tony's charms or challenges. Sure he did respond to a direct confrontation but in an aggressive and straight forward way that left no chance that he would come in second. Steve dismissed all his insults as nothing but there was the time to fight and confrontation was turned to cooperation.
After everything was settled they fell into that pattern. Steve would look at him sternly not paying any attention to his words, smarts or insults, he just waited for results. And Tony gave him results only to receive a nod of acknowledgment, nothing more. No pats on the back, no smiles, no jokes, no late night drinks. That was what men did together but Steve just stood there waiting for the next assignment like he was made from steel not flesh.
Tony wasn't sure why was that bugging him so much. Why did he want Steve's approval in the first place?
A note maybe? Worth continuing?