This is probably going to be 2 parts since I have 13 to do and these are gonna be pretty long. So bare with me as I get the second one of them out. 

Also, I'm thinking about adding Carol into the preferences and the list of characters I'll do imagined for! What do you guys think? 

Steve-

You and Steve had been friends since the moment you met. There was something that just automatically clicked when you were together. You knew how to make him smile after a hard day and he knew how to do the same for you. The only thing you didn't catch onto was his feelings for you, you were absolutely oblivious. You were even more oblivious to the fact that Steve would get extremely jealous whenever you would go out with Tony on errands for the team. Of course Tony knew about Steve's feelings so he would make sure to try to flirt with you when Steve was around. One day you were making dinner with Tony when Steve walked into the room and visibly tensed. 

"So Y/N/N, anyone you have your eyes on?" Tony asked with a wink, trying to get under Steve's skin. Steve rolled his eyes as you laughed. 

"Honestly yes but it's not like I'm going to tell you." You said as you moved onto to another portion of dinner. 

"So it's me?" Tony smirked as he moved closer to you. 

"Keep dreaming Tony." You rolled your eyes and turned around, seeing an extremely pissed off Steve. "Oh, hey Rodgers." You said with a shy smile. 

"Stark what the hell?" Steve almost yelled at Tony making your eyes widen. 

"Whoa there Steve what's going on?" You asked making Steve look at you and his eyes soften. 

"Um, I need to talk to you in private." Steve said rubbing the back of his neck. 

"Good luck Rodgers." Tony said smirking as he walked out of the room. 

You looked at Steve, ready for him to start talking and sighed when he didn't. "Steve, you know you can tell me anything." You said with a smile on your face as you reached out and touched his hand. 

"I like you Y/N, a lot. I would love to go on a date with you but I was too scared and I didn't want to ruin our friendship. I just, I couldn't get the courage to ask you. I just...I can't stand it when Tony flirts with you, he does it on purpose you know that right? I just-" Steve was cut off by you grabbing his shirt and pulling him to you and kissing him. 

"Finally! All of my hard work has paid off!" Tony yelled from the doorway making you two pull away and laugh. 

You got back to making dinner, but instead of Tony helping, Steve was right by your side. 

Tony-

We all know Tony would be very jealous whenever another male avenger made you laugh, and he really did. The thing is, you didn't know he had feelings for you. You had your suspicions but you didn't know for sure if he did or not. One time when Clint was sparring with you, me knocked you down and was on top of you when he started to tickle you. It wasn't out of the ordinary because you and Clint were best friends. Tony walked in on this scene and scowled at you two. 

"It's a gym, not a bedroom." He muttered as he made his way to a punching bag. 

"I heard that! I'm not into Y/N! Ew!" Clint yelled making you shove him off of you and get up. 

"Tony what did you say?" You asked as you leaned on the ropes of the ring. 

"Nothing." He spat at you making you raise your eyebrows and scoff. 

"Get in the ring mister. You obviously want to fight something." You said and he dragged his feet into the ring. 

Once the fight was started, he took you down very quickly. 

"Since you're finally on top of me, is all you're gonna do is stare at me?" You asked with a smirk. He leaned down and kissed you, catching you by surprise but you quickly kissed back. Clint finally had to yell at you two to stop making out in the middle of the ring. 

Tony smiled down at you and you laughed gently. "What took you so long Stark?" You asked making him laugh. 

"I have no idea." He whispered before kissing you again. 

At this point, Clint had lost the motivation of trying to stop the two of you from making out, so he walked out of the gym. It was a good thing he stopped trying since it was a battle he wouldn't win. 

Thor-

The only person who could get under Thor's skin was Loki, and he was amazing at annoying Thor when it came to you. Whenever you would talk to Loki, which was a lot since he made sure to talk to you a bunch. One day Thor had enough when Loki was being particularly flirty with you. 

"Excuse me Y/N, you want to head to the gym? I think it's our turn to train. Of course there's another way to train." Loki said with a wink. You rolled your eyes and playfully shoved Loki off the couch but Thor was fuming on the other side of you. You noticed his body stiffen and looked over to him. 

"You good Thor?" You asked looking over to him. Thor didn't reply, but he stood up and walked out of the room. "What'd you do this time Loki?" You asked turning to his brother. 

"Nothing!" Loki said with his hands up in defense. "Okay I might be poking at his jealousy since he is very fond of you." Loki finally gave in when you gave him a hard glare. 

You sat there for a second before running to go find Thor. You found him on the balcony staring off into the trees that surrounded the compound. 

"Hey." You said walking over to him and leaning her back against the rail to face him. "Want to tell me what that was all about?" You asked looking up at him. 

"I got jealous and angry at my brother." Thor simply replied but still didn't look at you. You simply nudged his arm to get him to explain a little more. He sighed and looked down at you. "I may have feelings for you." He added and you looked up at him and smiled gently. 

"You, the God of Thunder, has feelings for me?" You asked with a smile on your face. Thor's face turned a little pink as he nodded. "Well it's a good thing I kind of have feelings for him too." You added making his face light up. 

Thor smiled before he pulled you into a bone crushing hug. He let go before you were crushed. You laughed and looked at him. "How about I take you on a date?" Thor asked making your cheeks flush pink. 

"I would like that very much." You said, this made him smile even wider and wrap you up in another bone crushing hug. 

Clint-

Scott was the new jokester on the team, and that title was initially held by Clint. You had a thing for people that could make you laugh and Clint knew that. When Scott came to the team and made everyone laugh, Clint immediately didn't like him. You were hanging out with Scott one day, trying to come up with the worst jokes you could think of. It had both of you doubled over in laughter. When Clint got to the room to get Scott for training, he rolled his eyes and called Scott. 

"Hey Scott, your turn for training. You're stuck with me today." Clint called making Scott stand up and say goodbye to you and following Clint to the gym. 

You stayed on the couch and stayed there until you thought of the perfect joke to tell Scott. You made your way to the gym and when you got there you saw Clint aim an arrow at Scott and barely miss his head. 

"Clint! What the hell was that? When we spar you do not do that!" You yelled making the pair stop and look at you. Clint sighed and nodded a little and put the arrows back in the quiver. 

"Forgot." Clint simply said and walked out of the ring. 

"You forgot? That's a lie if I ever heard one. Get your ass over here and tell me what the hell is going on with you." You said, a little pissed at the archer. 

Clint walked over to you and you gave him a face, to make him start explaining what was going on. "Scott kind of took over being your best friend when he got here. I just....You've been my best friend since we started and I like you a lot and I got jealous over him being with you all the time and making you laugh." He explained in a low voice. 

You looked at him for a second and nodded a little bit. "You could have just told me Clint, you know that I like guys who can make me laugh. Scott was just kind of there and since he's missing his daughter I kind of took over that role. I only have eyes for archers." You said with a smile. He took a second to process what you said and when he realized what you said he smiled and seemed like he could jump up and down with excitement. 

Clint pulled you into a hug and made you laugh. "You know I love your hugs but you're sweaty and I'm not into sweaty archers. Hit the showers." You said laughing as you pushed him away. 

"Care to join me?" Clint said with a smirk and a wink. 

"Hit the showers alone." You laughed and rolled your eyes. You pushed him towards the guys locker room and rolled your eyes once more. 

Natasha-

You and Natasha were really close but what you didn't realize is that you didn't know that Natasha had a huge crush on you. So whenever you were talking with someone and they casually started to flirt with you, she would get pissed at that person for a day. You got sick of her basically hating everyone you talked to, so you confronted her about it. 

"So why'd you yell at Steve the other day?" You casually asked her when you two were watching Supernatural one day. 

Natasha kept staring at the screen and shrugged. "He just pissed me off that day." She casually responded. 

"That's not true." You said as you paused the show. 

"Come on Y/N!" Natasha yelled but stopped when she saw the look on your face. "Okay fine, I'll tell you the truth. His all mighty attitude is getting tiring." She finally said and you rolled your eyes at this lie. 

"Natasha if you keep on lying to me, I can't trust you on missions." You said, you saw her face fall. 

"Fine, I like you." She said and looked down at the table in front of her. You smiled and moved closer to her. 

"You may be a good spy but you can be pretty oblivious about feelings." You said making her look up at you with a confused look on her face. "I like you, you silly butt." You added making her laugh and roll her eyes. 

"I guess I am a little oblivious." She said and pulled you close, kissing you. 

"Whoa, really you two? If you two are gonna make out can you do it in one of your rooms?" Clint yelled from the doorway covering his eyes. 

You two pulled away and laughed gently before Natasha got up and offered you her hand. "Good idea Clint! Thanks!" She said as you took her hand and she dragged you to her room. 

"Damn it." Clint muttered as he sat on the couch. "Now they're gonna be annoying with that." He mumbled as he continued with Supernatural. 

Bruce- 

You were in the lab a lot with Bruce and Tony since you were super smart like Bruce. You and him were really close, but Tony liked to mess with you like he was your brother. Only Bruce thought he was flirting with you, like he always does. Whenever you were in the lab with Bruce and Tony walked in, Bruce would practically push you out the door and not want you back in until Tony had left. One day you were in the lab alone and then both of the science brothers walked in. 

"Hey Y/N, whatcha working on?" Tony asked making Bruce snap his attention over to you and curse himself for not coming up with an excuse to get you out of the lab. 

"Just a small project I've been working on as a present for someone." You responded casually, hopefully not giving away that you were making a gift for Bruce. 

"For whom? Is it me? I bet it's for me Bruce." Tony said starting to really bother Bruce, 

"Not everything is about you Tony." Bruce said as he started his work on the other side of the room. 

"It's not for you Tony. It's for Bruce so shut up." You whispered and Tony laughed and winked. 

"I told you it was for me Brucie!" Tony exclaimed making Bruce get up and walk out of the room. You shot Tony a look before running after Bruce. 

"Bruce!" You called as you caught up with him. "The gift isn't for him. Even if it was for him it wouldn't matter. You know Tony is like a brother to me." You said when he finally stopped walking. 

"A brother to you?" Bruce asked and tried to make his face look calmer than he was on the inside. He was more embarrassed that he thought you were into Tony but you were just his friend. 

"Of course I don't like Tony. I like you, oh and the gift I'm working on is a shirt and pants that won't rip when you become the hulk so you don't have to be half naked." You said with a smile. Bruce looked at you for a minute and smiled. 

"Thank you." He whispered and hugged you tightly. 

"Of course Brucie." You responded and wrapped your arms around him. You stayed like that for a few minutes before pulling away. 

"How about I take you on a date? Tonight?" He asked with a shy smile on his face. 

"I would love that." You said. "We should also go back to the lab." You added and he nodded. "Come on." You gestured and offered him your hand. He smiled and took your hand as you two started on your way back to the lab.