Clint Barton/ Hawkeye

You were putting away dishes after having an amazing lunch that Clint had made all by himself. Just as you put away the last dish, you felt Lucky head butt your leg. You looked down to see the dog had some kind of purple ribbon tied around his neck with something shiny dangling from it.

"Watcha got boy?" you said, kneeling down and pulling the ribbon carefully. You took the shiny thing in your hand and saw that it was a beautiful engagement ring.

Your eyes widened a little as you looked at it. You heard Clint clear his throat behind you.

"I'm the one that's meant to do the kneeling here," he grinned. Your eyes filled with tears as he took the ring from you.

"Y/N, you're the best thing that's ever happened to me. You laugh at my lame jokes, you faithfully wait for me to return from long missions and you always know just what to say. Y/N L/N, if I asked you to marry me, would you run away?" You were crying tears of joy by now.

"Of course I'll marry you Clint!" Clint smiled widely and slipped the ring on your finger. You tackled him and kissed him deeply. The moment was killed when Lucky jumped on the two of you and licked you both.

...

Tony Stark/ Iron Man

One night, Tony had arranged for a fancy dinner on top of the tower. The meal consisted of your favourite foods and your favourite drink. Once you had finished eating, Tony stood up and extended his hand.

"Can I have this dance?" You took his hand and as soon as you did, your song started playing. As you started swaying to the music, you couldn't help but think of how perfect tonight had been.

"So, what did you do?" you asked, looking up at him.

"What do you mean?" he smirked.

"Well... it's not an anniversary or something special like that, so it makes me think that you did something monumentally stupid that you're trying to make up for."

"Ah, but that's where you're wrong Babydoll, tonight is a special night"

"How so?"

"Because... tonight I ask the most beautiful artist in all of New York to be my wife." You were stunned.

"Wh-what?" Tony pulled away, got down on one knee and presented a ring box with a stunning ring in it.

"Y/N, never in my life did I think that I'd ever want to settle down but when we started dating, all that changed. I want to get married to you, have kids with you, grow old with you. Will you do me the honour of becoming Mrs. Stark?"  You were tearing up by now.

"Yes Tony, I will!" Tony smiled, slipped the ring on your finger and stood up before giving you a passionate kiss.

...

Pietro Maximoff/ Quick Silver

You were getting ready for one of Tony's parties. You didn't really want to go to this one, but Pietro had insisted. You gave yourself one last look in the mirror, before going to meet with Pietro. When he saw you, he was positively giddy.

"How do I look?" He looked you up and down.

"Good, but I have something that might make your outfit look better. I have to warn you though, it comes with a condition," he smirked.

"Oh, really? And what's the condition?" you asked, amusement lacing your voice. Pietro knelt on one knee and pulled a ring box out of his pocket.

"You have to say yes," he said, opening the box.

"Pi... Pietro... are you asking me to marry you?" Pietro nodded, feeling slightly unsure of your reaction.

"Then my answer is yes." Pietro slipped the ring on your finger and stood up. He hugged you tightly instead of kissing you, knowing how long you had spent getting your hair and make-up ready.

"I'm glad you said yes, otherwise, going to our engagement party would've been very awkward.

"You mean... Tony knew about this?"

"Yep. Been planning this party ever since I showed him the ring." You smiled widely at his words. When you walked into the party, you didn't think you could get any happier.