Tony's eyes followed you from the lab. "Don't even think about it, Tony," Bruce said, not even looking up. "What?" Bruce scoffed lightly. "I saw that. Y/N is off limits, Tony." Tony rolled his eyes dramatically and got up from his chair. He knew Bruce was protective of you, but he also knew you could take care of yourself.

You weren't like the other people Tony was usually attracted to. You were quiet and kind-hearted. You saw the best in people, but you would put people in their place if necessary. With words. You weren't Enhanced. You didn't have powers. Your brain was your weapon. Tony loved it. Bruce was the only thing standing in his way and he didn't know why. So, he decided to ask his friend.

"Why do you have a problem with idea of me being with Y/N?" Bruce looked up at Tony and took off his glasses. "You forget that I've been living here with you for a long time. I've seen how you treat the people you date. Love 'em and leave 'em. No one lasts and I won't let you do that to Y/N." That hurt Tony. Bruce wasn't normally so vocal about Tony's flaws, but when it came to you, he was going to everything in his power to protect you. Now, Tony was determined to prove Bruce wrong.

He left the lab and went after you. You hadn't made it very far before he found you. "Y/N!" You looked over your shoulder at him with a smile. "Hey, Tony. What's up?" Tony caught up to you and asked you on a date. "You want to date me?" Tony nodded. "Yes." You bit your lip. "I don't know, Tony. I'm not exactly like anyone else you've dated." Tony grinned. "Exactly. You're different and I'd like a chance to show you how much a appreciate it." You smiled sheepishly. "Alright. Pick me up for lunch in an hour." With that, you turned and walked away.

*short time skip*

Bruce was in the lab again when he heard your and Tony's laughter. The two of you came walking into the lab hand-in-hand. He cut his eyes at Tony, but didn't say anything. The two of you had been out several times and Bruce wasn't happy about it. Tony had gone behind his back and asked you out even after Bruce had told him his worries.

"What's the look for, Bruce?" you asked, earning a tight smile. "Nothing." You shrugged and turned back to Tony. "We still on for dinner tomorrow?" Tony nodded and brought your hand up to his lips. "Of course." You laughed and hugged him quickly. Tony gave you a little squeeze and kissed your temple, a gesture that had Bruce confused. That wasn't something Tony normally did.

You left the lab and Tony turned to Bruce. "I thought I said to leave Y/N alone." Tony shrugged. "Banner, I know what you said, but I promise I'm not going to hurt Y/N. There's something about your sibling that makes me want to be better. I don't want to be with anyone else. I don't want to hurt Y/N." Bruce hummed and Tony knew the conversation was over for now. So, he went back out to find you.

Bruce followed after Tony a few minutes later. He found him sitting on a couch in the living room with you. "It'll be okay, Tony. Bruce will come around," he heard you say. "What if he doesn't, Y/N? I don't want to leave you, but my friendship with Banner is important too." Bruce stopped walking to just listen. He'd never heard Tony sound so vulnerable before. You brought that out in him.

"I want you to be happy, Y/N and I know that you won't be really happy unless your brother gives his approval." You sighed and rested your head on Tony's shoulder. "I am happy, Tony. I love my brother and his blessing is important to me, but you make me happy. You would think he'd approve of that."

"I do," Bruce finally spoke up. You sat up and whipped your head around to see him standing there. Tony's dark eyes went wide. "You what?" Bruce came the rest of the way into the room, his hands in his pockets. "I was wrong. You obviously care for Y/N more than anyone else before. You past is just that. The past. As long as you care for Y/N and them happy, then I approve." You got up from your seat and moved to hug Bruce. "Thank you, Bruce." He smiled softly and hugged you tight.

"Thanks, Banner," Tony said. Bruce let you go and, in a warning tone, said, "I mean it, Tony. Don't hurt Y/N. The Other Guy is pretty fond of them and not quite as fond of you." Without another word, he let you go and left the room. Tony came over and put a hand on your shoulder. "He was joking, right?"