So.... Tony and Pepper were at a Press Conference to launch an eco-friendly product that Tony had designed. It was a filter for polluted ocean water that worked on thousands of litres at once.
They were about to start when Tony's phone rung and he took it out. "Hello?" Tony said. "OK I guess you said hello to me". Peter said. "What did you do?" Tony asked. "I'll cut the chase. I might have gone deaf cause of an explosion and now I'm going to the Tower". Peter said.
Tony immediately got up. "Peter? Peterrr?" Tony spoke loudly. He whispered the matter in Pepper's ear. "Ah sorry everyone something came up. We'll be rescheduling the launch for some other time". Pepper said getting down the stage with Tony.
"Who was the person you were talking to on phone Mr. Stark?" A reporter asked. "Ah it's a family matter". Tony said avoiding him. "Is he the son of Captain America?" Another asked. "What? No!! He's my son.". Tony said getting in the car.
"You gave them something to really spice things on". Pepper said as Tony drove away. "What did you expect. He's gone deaf". Tony whined. "Wait deaf!!! You said he had an injury". Pepper yelled. "Well I didn't want to worry you". Tony said. "Worry! Tony drive fast our son has gone fucking deaf and you expect me not to worry". Pepper yelled.
Tony increased the speed with a smirk on his face. Speeding tickets were no problem. Peter was in trouble that mattered. They drove to the Tower in minutes.
They found him sitting in med bay with Bruce patching up his ears. "OK tell me he'll be alright". Tony said. "I think it'll take time to heal?" Bruce said. "How much? How much time?" Pepper said. "Ah about a week". Bruce said.
Tony and Pepper breathed a sigh of relief. They walked to Peter and he looked up to them smiling. "Hi Mr. Stark, Miss Potts".Peter greeted. Tony and Pepper hugged him. "I think it's alright and if you say something mumbling in my chest I can't get it." Peter joked.
"You scared me". Tony mouthed. Peter waved his hand like it was nothing. "Bruce said it'll be a week before I eat your ear off". Peter said. "I would have pinched your ear and given you a scolding but you have got injury on your ear only so you are saved. Pepper said.
" I didn't get it. I can't hear Miss. Potts". Peter said. Pepper wrote it on a notepad. Peter raised his hands in surrendering manner. "Lucky me I'm saved". Peter said. They walked out into the living room. "Tony why is everybody asking who Peter is and how is he your son?" Steve asked.
Tony facepalmed. "A reporter asked where we were going after ditching the conference and we said family matter". Pepper said. "He must have heard me saying 'Peter' so he asked if he was your son and I said if he was anyone's he was my son". Tony said. The Avengers burst out laughing.
Peter looked at everyone. "What happened?" Peter asked tucking Natasha's sleeve. "Huh what happened to your ears?" She asked. "He's gone temporary deaf for about a week". Tony said. "WHAT!!!" They exclaimed. "Sign language?" Natasha asked. Peter nodded. "You know sign language?" Tony asked. "I guess you asked how I know sign language so I was bored and you tube offered me the tutorial." Peter yelled.
They talked in sign language. "What were you all laughing about?"Peter asked."A reporter asked if you were Steve's son and Tony said if you are anyone's you are his son". Natasha said signing. Peter jumped on Tony. "Aww I love you too". Peter said in his neck fully clutching Tony like a spider.
Tony smiled. "He's mine. So you all stay away I decide who he spends time with.". Tony taunted. "What that's not fair.". Natasha said. "I'm an Uncle you bastard I'll hunt you done if that's what it takes to spend time with him". Rhodey and Clint said. "Jezz alright alright". Tony said.
"We need to give an official statement about Peter. Say he's your Intern and you think of him as your son". Pepper said. May was there now. "Peter you'll give me a heart attack one day". She wrote down. Peter saddened up like a puppy.
"You are lucky you are cute". She wrote and Peter grinned. "So what are you gonna do about the little stunt you pulled?" May asked Tony. Pepper told her the whole plan and she agreed.
The day of press conference came. "Who's Peter Mr. Stark?" A reporter spoke loudly. "Ahh..." He looked at Pepper. "He's my and Pepper's adopted son. The future heir of Stark Industries and bearer of our legacy. Peace". Tony said walking down from the stage holding Pepper's hand and got in his car.
"I can't trust your public statements ever again". Pepper said. "So you don't want to be his mother?" Tony asked smirking. "Shut up. He's my son". Pepper said.
So basically yeah they adopted him officially after having a talk with May.