Tony's not surprised Cap is the only one of them who had gotten a dose of the red stuff--he'd been in the middle of everything, as per usual--saving civilians and agents and kicking robot ass for the Free World. He's a little more surprised to discover that Darcy had been one of those agents. And by the time they're all stuck in the elevator together--Steve and Darcy pressed together in one corner, everybody else in the other—it doesn’t take long to figure out why the stupid villain they’d been fighting had stopped to fondle one of his bots

"In which Darcy gets Steve's number and proceeds to drag him into the modern world via text messaging and their friends start to ship it."