Based on Irondad fic ideas #8 and #18 by idk-bruh-20 on Tumblr.

It was a rainy April afternoon, and Tony was testing a new suit function. He had waited all day until Peter could be there to do the trials. Partially because it was easier with an assistant, and partially because he knew Peter would freak out over how cool it was after working on it with him for weeks. He was using his basic design from a current suit, but introducing some nanotech to seal up previously weak areas (like where Ant-man had gotten inside and caused havoc) and to make a lot of the joints more flexible. He was also testing some failsafe functions like the nanotech being able to fill in for any missing or damaged areas in the middle of a battle. He and Peter had been focused on it for the last 6-8 weeks, and today it was go-time to see if that nanotech would respond as it was programmed to.

"You ready, Mr. Stark?" The kid was practically vibrating with excitement.

"Flip the switch when I say, kid, and turn them loose."

"Ok."

"Now!"

"Do you see a progress bar? It should be up right now."

"Yep!"

"Talk to me. Tell me what you see." It would be easier for FRIDAY to do all this communicating, but Peter was way more enthusiastic than his long-suffering AI.

"It's here; ready to go."

"Press 'control n'."

"N. That wasn't it, sir."

"Oh, sorry. N. Enter."

"Got it! It's working, Tony!" The older man grinned. The kid was beside himself as he watched the nanites stream out of the housing unit and basically disappear across the suit. He'd even slipped and called him "Tony," which he had been doing a little more often lately.

"Come over here and let's scan to see if I'm all sealed up."

All of a sudden, Tony's knees almost buckled as he had a flashback to a nearly identical conversation he'd had with his first assistant when testing the Iron Man armor. His gauntleted hand flew to his head to support the slight explosive feeling in his brain, and he saw scenes from the cave flash before his eyes. Yinsen speaking kindly to him. Yinsen gently questioning him, and helping him understand that maybe his priorities had been in the wrong places. Yinsen almost cheerfully sacrificing for him, the man who had built the weapons which had destroyed the man's family and village. For the young hotshot billionaire who was so self-absorbed that he never even asked the right questions. Peaceful, patient, brilliant Yinsen, who helped and served him in any way he could. Who had saved his life in more ways than one.

Abruptly Tony's tunnel vision reversed, and he found himself sitting on the ground, fully encased in the armor, minus his helmet), a very concerned Spider-child crouched down at eye level, holding his shoulders. "Mr. Stark? Tony? Please, sir, can you hear me?"

"Whoa. Sorry, kid. I'm okay. I'm fine." He shook his head slightly, and tried to gather his wits. Peter looked on the verge of a breakdown himself.

"What happened, sir? I almost called 911, or Pepper, or someone, but FRIDAY said you were probably just having a panic attack or a flashback, and that I should give you a few minutes before doing anything drastic." His eyes were slightly red-rimmed, like tears had been close, even if they hadn't fallen.

Tony stood up a bit unsteadily, with Peter's hand supporting him as soon as the kid realized what he was doing.

"FRIDAY? Was the test successful?"

"It seemed to be, Boss, though we didn't get a chance to test some of the extra functions, of course."

"Okay. Great. Excellent. We'll do that next time, yeah? Disassemble the suit, please."

Peter stepped back as the pieces returned to their storage area, the nanotech bleeding quickly into its tiny housing unit first. The boy watched in awe, but was also wrapping both arms around his torso. He was obviously still shaken.

As soon as the armor retreated, Tony stepped forward and pulled Peter in for a hug, using a hand at the back of the boy's head to guide it down to his shoulder. Peter's breathing hitched, and the mechanic was pretty sure a few tears finally broke loose.

"Sorry, sir, I—" Peter half heartedly tried to pull back out of Tony's arms, but Tony held tightly, and rubbed the other hand soothingly up and down the kid's back a few times, pressing his cheek against his hair. It was still all gelled down from school, and Tony had to resist the urge to run his fingers through it to loosen it up.

"Sorry, Pete. I'm sure that was unsettling for you. It was just kind of an all-consuming flashback, from my time in Afghanistan. Not so much scary as just… intense. I'm sorry that happened while you were here."

"I'm not." This time Peter did pull back, taking a step away so he could face Tony. "I'm glad I was here, instead of you being alone." He rubbed a sleeve across his face and took a cleansing breath, pulling himself together quickly.

Tony couldn't help but notice the further parallels. How much worse would his time in Afghanistan have been if he'd been alone instead of with Yinsen? Could he have built the suit without Yinsen's help? Would he have escaped? Would he have even tried?

"Is that how you want to go out? Is this the last act of defiance of the great Tony Stark, or are you going to do something about it?"

He shook his head a bit, trying to clear it.

"Hey, kid, you ever play Backgammon?"

"Uh, no. Isn't that kind of an old person game?" Peter asked, head tilting doubtfully.

"Huh. Well, I'll teach you. I'm kind of an old person." He clapped Peter on the shoulder, steering him towards the door. Enough workshop ghosts for today; they were spending the rest of the afternoon in the penthouse.

"Mr. Stark," Peter rolled his eyes, bumping against his mentor's shoulder. "You are not."

"That's not what you said the other day." Tony tousled his hair, ruining the sleek lines it had been pressed into that morning. Peter yelped and ducked away, but he was laughing, tears fully dry, and he was back against Tony's shoulder almost immediately.

"Got a family?"

"Yes, and I will see them when I leave here. And you, Stark?"

"No."

"No. So, you're a man who has everything, and nothing."

Yinsen's face was in his mind as clearly as he had seen it that day.

"Thank you for saving me."

"Don't waste it. Don't waste your life."

He was trying not to. And finally, he felt like he could have answered the man's earlier question differently. Pepper's face, Peter's, Rhodey's, and Vision's scrolled through his mind. More painfully, but still there, he saw Nat, Bruce,Thor, Clint, even… even Steve. Yes, he had a family. It was not very traditional, and broken, but still good. He finally had something instead of nothing, and he was trying his best to live for it, for them. And Yinsen had been right. It was everything.