Tony doesn't mean to play games. It's not his intention, he's not trying to trip anyone up. It's just that he's been by himself for so long, his communication skills have suffered slightly. He can still communicate a plan or an idea, but sometimes his train of thought kind of gets derailed, and he's the only one who can really follow it. Sometimes, Tony's talking is just noise, it doesn't mean anything. Just him, not being able to stand silence and filling it with useless talk. (Most people just tune it out. Steve listens to every word.)
Sometimes, Tony forgets to say things. Important things. Like, "I love you." Even after a year.
Steve's wondered, on occasion, if he should be more annoyed that Tony's never said it, but then he realizes how worthless words are to Tony, at least when they're coming from himself; they're just something you kind of fling around to get the results you want.
Steve thinks about how Tony draws equations all over Steve's arm when they watch movies, trailing from the back of his hand up to his shoulder. Works of art in mathematical precision.
He thinks about the times when Tony tried to cook for him on various occasions, and how they'd silently compete to see who could eat more of it before they both cracked and ordered take out.
He remembers fingers carding through his hair, and lips pressed to his neck, warm skin pressed together, limbs all tangled together. No heat, just soft affection in the morning sun.
He remembers the night Tony took his shirt off for the first time in front of Steve, and how Tony's hands had shook just a little, when Steve took them in his.
He thinks about that horribly guilty look Tony gets when he realizes how long he's been down in the lab ignoring Steve, and how he'll start apologizing and he won't stop until Steve kisses him quiet.
He'll remember the night he told Tony he loved him, and Tony starting apologizing, as though he had tricked Steve into somehow. Tony had told him not to waste his time, there were better people out there, especially for Captain America, and Steve remembers how his chest ached in sympathy for someone so beautiful convinced they were so worthless. It took him almost two months before he could say it without Tony flinching.
Suddenly, three stupid little words didn't mean so much. Because Tony had already told Steve, over and over in his own abstract way, exactly what he wanted to hear.
He wouldn't trade it for the world.