When the first words out of the mouth of his childhood hero are, "You must be Anthony Stark. I was friends with your father," that drop in his stomach goes far beyond 'disheartened' and straight into the zone of 'disappointed-devastated-jealous-angry'. He's being compared to his father again, and while it may be meant as a complimentary sort of thing by Captain Boyscout, it has the exact opposite effect on Tony Stark, Iron Man, Genius, Billionaire, Playboy, Philanthropist, Man Who Is Trying Damned Hard Not To Be His Father. Tony doesn't understand; he is doing his best here to do the right thing, to help people, throw his very body between innocents and the forces of evil, and that always leaves him in the lurch when it comes to friends. Of course, he has Pepper, and he has Rhodey, but he doesn't have them, not really, and JARVIS and Dummy are still computers at the end of the day. His father's weapons were more numerous than all the breaths the man took in his entire life. He was cold, a businessman, a drunk; the name Stark had never suited anyone better. But even with all that, his father had had people like this, had been friends with goddamn Captain America.
He shakes the guy's hand (he looked so earnest, like a little boy or a puppy, how could Tony not?) and gives him a stiff smile. "Well, it was nice meeting you, but I'd better get going. See you around, Cap!" He swans off, doing his best to look rich, vacant, carefree, when he actually wants to rip up his old man's gravestone. When all he wants to do is get up in newly-revived Steve Rogers's face and shout 'My father is dead,' 'I'm nothing like him' and 'You must not have known him well' and 'He gave up searching for you' and 'Why, why were you his friend?'. All of these things fighting their way up his chest, past the arc reactor, through the knot in his throat are equally repulsive and inappropriate, especially with Nick effing Fury standing right there, and oh jesus, he would send Tony such a laser-hot glare that both Tony and the eye patch would catch fire.
Maybe he should just…keep his distance from Captain His-father's-friend. Especially since his father's last friend had tried to kill him via removal of the thing that kept his heart beating.
Yeah. He'd have to rethink this Avengers Initiative thing.