Tony started laughing without really knowing why. It was absurd, that's why-- one, for Steve acknowledging the name the S.H.I.E.L.D. agents would use over the comms without prompt or its due level of resentment, two, because he was sure a 'popsicle stand' wasn't a real thing and three, how in the hell was that Steve's first impulse? Eventually, Tony was laughing with his cheek pressed against Steve's arm, gripping his elbow and sputtering quite helplessly.
"I think you need to work on that," Tony suggested, high pitched and strained without enough air. Then he went, "Hey--" and dragged himself up to sit straight and point towards the fireworks. "Look at that," he said, not without a little bit of pride even through the puffing breaths of trailing hysterics. In the sky, great spheres were opening up and spreading through the stars, quickly one after the other to layer on top of each other-- red, white, red, blue-- and just as they made to melt away, a star bloomed at their centre. Tony had threatened, flattered and exploited experts to make that work.