"Does he seem...weirdly excited to you?"
Steve's tone was cautious, voice so low Tony almost didn't pick it up over the cheery, kid-friendly music that was playing in the workshop. (He and JARVIS had once spent a long afternoon debating what music was appropriate to play around a small child; Tony thought that Dummy had heard so much Nine Inch Nails as a bot that he was probably immune to any and all variations on the word "fuck", but JARVIS insisted that as an actual child, DJ should probably be learning his vocabulary from someone with less carnal intent.)
"Weirdly excited?" Tony asked, turning his head to look up from where he was slumped under one of Steve's arms on the couch. "Have you met the kid? Excited is his default state."
Steve's gaze drifted back over to DJ, who was dancing around the workshop with a sheet of HAPPY BIRTHDAY stickers, randomly sticking them to things.
"I mean, it's not his birthday," Steve said. "It's yours. He knows you're the one getting presents."
"Of course he's excited for my birthday, because I'm awesome," Tony said. "And he knows there's cake after dinner."
"He knows there's cake any time he makes big enough, sad enough eyes at Clint," Steve pointed out.
"Are you calling my kid weird?" Tony asked, narrowing his eyes.
"Yes. You and your child are both excessively weird," Steve said gravely.
"I take exception to that, excessively. We are exactly as weird as we're supposed to be," Tony said. "DJ! Stop laminating the workshop, come here."
DJ gave him a momentary pout, but put the sticker sheet down and came running over, clambering up on the couch.
"Happy day!" he chirped, spreading his arms wide.
"Thank you, yes, I am old," Tony said. DJ collapsed forward across Tony's lap and half of Steve's, heaving a satisfied sigh. "And you are heavy."
DJ rolled without warning, but both men had encountered this before; they lifted their legs in unison, and DJ zoomed down their legs to the floor, tumbling off their toes and giggling.
"Are you excited about dinner?" Tony asked, as DJ picked himself up and leaned on Tony's thighs. DJ shook his head. "Oh, you think you get to share my presents?"
DJ shook his head again, fingers flexing and releasing on Tony's knees.
"Good, because they're all mine, I'm greedy," Tony said. "Everything for Tony, nothing for DJ."
"After dinner," DJ said.
"Oh? You want cake?"
DJ shook his head more vigorously. "After," he insisted. "Rooftop!"
"For a tiny little agoraphobe, you sure seem excited about getting onto the roof," Tony said, lifting DJ by the armpits and floating him over his head. DJ kicked his legs like he was swimming. "You want to have dinner on the roof? We can have a picnic."
"YES!" DJ yelled.
"Okay, picnic it is. JARVIS, when is dinner?"
"Dr. Banner and Agent Barton inform me that the meal is ready," JARVIS said. "I have asked Thor to fetch some blankets for the picnic and the external heaters have been lit."
"Come on, then," Tony said, tossing DJ to Steve, who tucked him under one arm. "Picnic it is. Happy birthday to me..." he sang, as he led the way out.
"Bless," Steve said fondly, kissing DJ's hair. "Your enthusiasm is a powerful weapon. It's the first time I've seen him happy on his birthday."
"Days great," DJ informed him. He spread his arms and made a puffing noise, like a small explosion.
"You're great," Steve said.
"Come on, slackers," Tony called from down the hall. "Food time!"
Steve set DJ down and he bounced his way towards the penthouse, where the Avengers were carrying plates laden with food out onto the blanket-covered rooftop.
Dinner was a success, not that Avengers ever really turned down food. DJ spent much of it plonked in Rhodey's lap, in part because Rhodey had brought a large gift for Tony and a small gift for DJ, "So he won't feel left out." Tony had given DJ a nod and DJ had torn into the gift, eyes growing huge when it turned out to be an intricate cast-aluminum War Machine action figure.
"He'll have motorized it by breakfast," Tony said, finishing his cake as DJ explored every joint of the action figure systematically. "You didn't have to, Toast Crunch."
"I have to make sure I stay his favorite," Rhodey said. DJ deftly popped War Machine's left hand off, studied it, then popped the head off and put it on his arm, holding up for Rhodey's approval. Carol, leaning on his shoulder, took the hand from DJ and popped it in where his head should be.
"Facepalm," she said. DJ cracked up laughing.
"Well, this has been great," Tony said, setting his plate aside and adjusting the hideous hat Natasha had given him. She had an excellent sense of what to give the man who had everything, and Clint had given him matching hideous socks. "But it's getting chilly up here and I think it's time to go inside for the after-party."
"No," DJ said, alarmed. Tony frowned at him, perplexed.
"It's not bedtime, we just have to go inside," he said.
"Nooooo," DJ groaned, flopping back against Rhodey.
"What, you want to be carried?" Rhodey asked. DJ, looking genuinely upset, scrambled off his lap and darted towards the rail of the balcony.
"Oh, no, DJ, we talked about this -- " Steve caught him around the waist before he got very far. "No railing unless someone's holding onto you."
DJ wailed, startling everyone; Steve adjusted his hold to make sure he wasn't hurting him, but DJ didn't even seem to be aware of him.
"Nooooooo," DJ yelled. "Not inside!"
Steve gave Tony a hapless look; Tony dusted off his hands and stood, taking him from Steve's arms with difficulty.
"Are you tired?" he asked DJ, who shook his head and kept squirming. "Deej, come on, stop this. Hey!" he said sharply, and DJ did stop moving, but he gave him such a betrayed look. "Are you hurting? Did you have too much cake?"
"No," DJ said rebelliously.
"Are you still hungry? We have food inside, Deej."
"Not inside!" DJ insisted, and then pointed over the edge of the balcony's railing. "It."
Tony looked over his shoulder at the empty air over the Manhattan skyline. "What?" he asked. DJ made a frustrated noise. "Okay, hey, it's okay, find your words, take your time. We won't go inside until you explain. Deep breath, kiddo."
DJ inhaled, a gulping little half-sob. Tony shifted him to rest more comfortably in his arms.
"What's 'it'?" he asked.
DJ spread his arms and made a puffing noise.
"Did you see something?" Tony asked. DJ shook his head. "Are you waiting to see something?"
DJ nodded and made the gesture again. Behind him, Steve said, "Oh," as if he understood. Tony raised an eyebrow at him over DJ's shoulder.
"Are you waiting for the fireworks, DJ?" Steve asked.
"Fireworks?" Tony asked, startled. DJ was nodding in his arms and pointing over the rail.
"He doesn't want to go inside because he'll miss the fireworks," Steve said.
"Are there fireworks?" Tony said, voice rising in bewilderment.
"Well, the last birthday was mine," Steve said.
"Oh," Natasha said. Tony felt understanding dawn.
"And there were fireworks because it was the Fourth," he said.
"But it's the first birthday DJ ever came to," Steve continued. He leaned in and brushed DJ's disarrayed hair off his forehead. "You think that's how it goes, huh? Cake, presents, then fireworks?"
DJ nodded, but the expression on his face said he was realizing his mistake.
"None?" he asked forlornly.
Steve smiled. "He was excited because he thought Manhattan would have fireworks for your birthday, like we did for mine," he said to Tony.
"None," DJ confirmed to himself, and faceplanted into Tony's chest sadly.
Tony gave Steve a tiny eyeroll, amusement tugging at his lips, but he made sure DJ couldn't see.
"Fireworks are only for Steve's birthday, because he's Captain America," Tony said. DJ sighed heavily. "Oh, my God, I'm about to be That Dad. JARVIS?"
"Sir?" JARVIS answered over the balcony's speaker system.
"How many of the new tower defense drones do we have fabricated?"
JARVIS sounded like he knew what was coming. "I imagine just enough, Sir."
"Okay. Run simulation twelve, the combat optical test."
"Shall I throw in some color filters, Sir?"
"Yeah," Tony said, settling down again on one of the blankets. There was the sound of a door sliding open, somewhere below their feet. "Oh, and notify the cops and put a tweet out, would you? I don't need the neighbors freaking out that we're being attacked."
Steve sat next to him, head tilted his way curiously, and the others joined them on the blanket. Rhodey, who was probably the only one who knew what was coming, sat on Tony's other side and opened a beer.
"Dry eyes," Tony whispered to DJ, turning him in his arms. "Come on, look up, you're gonna miss it."
DJ wiped a hand across his face and turned it up to the sky just in time to see a bevy of Stark next-generation drones fly across the shadow of the moon, splitting into two formations over their heads. There was a crackle, and then an opening volley of shots, and drones began darting around each other, occasionally exploding spectacularly, flashes of light going off all around them. Colored smoke drifted around them, sucked into gaps by drone engines or dissipated by their propellers. One went off with an especially loud noise, flaming debris falling through the sky; two more darted after it, caught fire, and also exploded. DJ cheered.
"Bloodthirsty pup," Tony murmured, grinning. DJ pointed at a drone that was spewing green smoke and chasing another with a constantly flashing pattern of lights. Steve leaned into Tony's side, draping an arm around his shoulders, as entranced as DJ was by the battle raging over their heads.
"Oh!" Carol said, looking suddenly excited. "Hey, I got this," she added, and lifted off the balcony, diving into the middle of the fight, light bursting from her fists occasionally as she joined in. Rhodey whistled and applauded.
The light show lasted about twenty-five minutes; DJ didn't look away from it once, though about halfway through Tony started studying the realtime readings from the surviving drones on his phone. Carol touched back down once most of them had been wrecked, and at last there were only two left. Then, with a wheezing rattle, one of them rammed into the other, which exploded in bright crimson smoke.
The champion drone, making a worrying clicking noise, beeped briefly as JARVIS took control of it, lowering it to the rooftop balcony and into DJ's lap. DJ patted it, then promptly popped the housing off and adjusted something inside. The clicking stopped, and a little blue light came on. The drone lifted off and wove its way towards the door to the penthouse, knocking into it a few times before DJ got to his feet and ran for the door, pushing it open and following it inside. Everyone else, folding up blankets and gathering up plates and leftovers from dinner, began to trail after.
"He thought all those fireworks were for me," Steve said, sliding his arm down to wrap around Tony's waist as they made their way inside. "I wonder if he thought the Fourth of July parade was, too."
"Well, he loves you," Tony said. "Of course you should have a big fireworks show and a parade on your birthday."
Steve hummed thoughtfully. "Probably cheaper than blowing up half a million dollars in Stark technology."
"Ehh, I was going to do it anyway, this just stepped up the timeline. I got a lot of really good data from it, actually, especially once Carol joined in -- "
"Mmhm," Steve said indulgently. "You keep telling yourself that."
"I did!" Tony looked indignant. "Are you questioning my dedication to engineering?"
"Perish the thought," Steve replied, watching Rhodey lift DJ up so he could try catching the drone, which darted out of his grasp. "I'm definitely not questioning your dedication to DJ."
Tony shrugged awkwardly. "He asks for so little," he said after a moment. "Really, in the grand scheme of things, he doesn't want very much. I'm not good at giving presents anyway, so it's hard to...give him things. And when he does really want something, it's always a surprise, sometimes I can't just snap my fingers and make it happen. So when I can..." he held up his hand and snapped his fingers. The drone drifted over and hovered over his hand, so Tony spread his palm out and let it land. DJ came running over and Tony passed it to him.
"Go put it up in the workshop, we'll tinker with it tomorrow," he told DJ, who took off running. "That kid never walks anywhere, it makes me tired just looking at him."
"Says the man who put rollerskates on his armor."
"ONE armor, and they're called electrostatic gliders, thank you very much."
"They're rollerskates, they have wheels you took off a pair of Wheelies. Hey, JARVIS, whose birthday is next, anyway?" Steve asked, so as to get the last word before Tony could respond.
"I believe Agent Coulson's," JARVIS said. "Shall I lay in a supply of rockets and begin obtaining the necessary permits, Sir?"
"I like Brocades," Coulson told them, passing on his way to the elevators. "They're the symmetrical sphere kind."
"You would," Tony said, as if it were an insult.
"We're planning to go to Coney Island," Coulson continued. "I'm sure they'd love to have Stark Industries sponsor a fireworks show."
Tony planted his forehead against Steve's shoulder. "JARVIS, don't bother buying supplies, just find some small factory with a good safety record and buy it. I anticipate a lot of birthday fireworks in our future."
"Look at it this way, all that time you spent making explosives, you're going to be great at fireworks," Steve said, patting the back of his head consolingly.
"And as usual, my main competition is China," Tony groaned. Steve laughed. "It's not funny, they have a thousand year head start."
"Go on, go put DJ to bed. I have one more present for you when you're done," Steve said. Tony lifted his head.
"But you already gave me a present," he said.
"Yeah, but this one you have to unwrap in private," Steve said meaningfully. One of his hands squeezed Tony's butt gently, and a band of red formed across his cheekbones and the bridge of his nose.
"Oh," Tony said. "Right. Kid to bed, bonus present."
"Happy birthday," Steve told him, kissing him before letting him go.
"Yes," Tony agreed, with a smile on his face that Steve privately categorized as adorably goofy. "It was."