The first time she called Tony dad it's because he was lecturing her about her overnight field trip with the almost all male AcaDeca team and she replied with, "Don't worry, Dad, I know how to deal with boys." The dad part was said very sarcastically.

Tony didn't know how to respond, so he simply said, "Just stay out of trouble, kid."

The second time she said it, Tony was prepared. He was ruffling her curls when she let out an annoyed, "Stop messing with the hair, Dad."

And he quickly quipped, "Can't you let your old man show some affection?"

She didn't bat his hand away, but she did mumble a grouchy, "Whatever," and press her head further into his palm.

At first Tony thought she only ever called him dad when she was exasperated with him. The huffy way she always said it- sarcastic and a little annoyed- seemed to confirm his theory. It wasn't until months later that he realized he was wrong. She only said it when he was doing something that a dad might do. Lecturing. Cooking for her. Insisting on picking her up from school. And it slowly dawned on him that all the "dad"s were clues to what his actions were. And he realized that he was a dad.

The first Avengers to ever hear Petra call Tony dad were Steve, Clint, Natasha, and Bruce. Unfortunately for the rest of the Avengers, they weren't actually there to hear it, but they'll tell the story like they were.

It was a Friday night and they were cooking. Steve and Clint were frying something that smelled amazing over the stove. Natasha was cutting vegetables. And Bruce was baking. The four of them barely looked up from their tasks when Petra sauntered into the kitchen. She went immediately to the pantry and pulled out a box of cereal. She brought it with her to the other side of the counter where she grabbed a stool and sat, munching away.

"You gonna want more to eat after that?" Steve asked her, only looking away from his stir fry for a second.

"I'm good Captain Rogers. I actually need to head out pretty soon. I've got a party to go to."

For a moment Steve thought of lecturing Petra about how to be safe at parties but then his mind reminded him that this was Petra. She was the politest kid he ever met and she only had like two friends. There was no way she actually meant she would be going to that type of party. And just when his brain had completed that thought the information from when he'd briefly looked up at her made him spin around. Petra was wearing make-up, which wasn't necessarily unusual, but the style of it was very different than how she usually did it, and her top was made completely out of sparkly blue sequins.

It was certainly a party look. But Steve was too shocked to go into his be-careful-at-parties-speach and instead went with, "Nice shirt, kid. It'll look really cool under party lights."

This statement captured the attention of the other Avengers because the rest of them snapped around to look at her. Just as taken aback as Steve, they just added their own compliments about her outfit.

Petra knew the shirt was pretty low cut, but honestly it wasn't even the most scandalous top she had. Not that she wore those tops out much either, just around the tower. She hated clothing that made it feel like her movements were constricted. She and the team were all family anyways so she didn't care about wearing practically nothing around the tower.

It came as a shock to everybody when Tony froze at the doorway just as Petra had slid off her stool and said, "I'm heading out," and Tony replied with a stern, "Not in that shirt you're not!"

It wasn't until after the words were out of Tony's mouth that he realized how they'd sounded. But just as quickly as he caught his mistake Petra snapped back, "Geeze, Dad. Sorry, I forgot to ask if I could borrow your favorite shirt tonight."

Which was followed by Steve's, "That's Tony's shirt?"

And Bruce's, "You know none of us will make fun of you whatever you wear, right Tony?"

Without a pause, Clint added, "Besides, you look good in blue."

These comments drew a few snorts of laughter from various people, but Tony's expression remained serious. He tried again, "Listen, kid-" he took a step closer to her.

"Wait. Are you serious?" Petra asked in disbelief, her eyes wide.

Natasha jumped in, "Tony, let her wear what she wants. Be glad she isn't insisting on going out in the white blouse she wore Tuesday that was basically lingerie."

Tony didn't respond to Natasha. He wasn't worried about how much skin Petra was showing. He stepped close enough to Petra that he could see a light of anger in her eyes.

She was mad at him. Tony had never seen her actually mad at him.

She moved to walk past him just as he muttered, "There's a cut out in the back."

Petra heard him clearly the first time but her brain couldn't pull together why that mattered so her response was, "Huh?" and she turned back around to face him.

"There is a hole in the back of your top."

The rest of the Avengers looked uncomfortable but only Natasha spoke up, "I'm pretty sure her back being bare is fine, Tony." But right after she said it, a fearful look flashed in Petra's eyes. All the Avengers caught it.

Petra spun so her back faced Tony. "Can you see it?" Her voice was full of concern.

"Yeah, kid, you can see it."

Petra rushed out of the room faster than the rest of the Avengers could ask her what the problem was. They opted to shoot questioning looks to Tony.

"Watch out," he told them, "it looks like you're about to burn dinner." A lie. The cooking was still going along fine, but Tony sure as hell wasn't going to tell them about the brand scorched between Petra's shoulder blades, marking her with the insignia of Richard Parker's spider-modified-super-soldier- serum.

There was a reason even Petra's most racy shirts were all racerbacks.

Natasha gave him one of her don't bullshit me looks and he did his best to ignore it. After a moment, he saw her lip twitch up just enough that he was concerned.

"What?" he asked her with the slightest edge to his voice.

"So, Dad, huh?"