"Sugar High"
As soon as Phil entered the common area, he saw what JARVIS was talking about, although the giggling had been audible from the elevator. The Avengers were gathered around the coffee table, and empty packets of various candies littered the floor around them. They'd have to work it off later if he wanted to get any sleep.
"You're on a sugar high," he said, sending them into another fit of the giggles. "Again."
"Phil, Phil, Phil!" Bucky said, kneeling up higher and gesticulating towards the table. "Come look what I made for you!"
"It was a group effort, Barnes," Clint said, throwing candy frogs at Bucky, who just batted them away.
"Yeah, but it's from me," Bucky said, and he gestured Phil over. "C'mere. C'mon."
Phil sighed internally, but he dutifully walked towards his boyfriend, gingerly stepping between rubbish. He nearly tripped over when he glanced at the coffee table, covered in sweets, and saw that gummi worms were arranged to spell out 'WILL YOU MARRY ME, PHILIP COULSON?'
"My first name has two 'l's," he said absently. Bucky glared at Thor, who looked contrite.
"Someone got hungry," he muttered. But then he picked something up, shifted on leg so that he was on one knee, and held out a lollipop ring. "So, how `bout it? Wanna marry me?"
Phil opened and closed his mouth. Then said, "You're on a sugar high, Bucky."
"You didn't want something big and embarrassing," Bucky said, and Phil was surprised that he remembered that conversation. Wasn't that five months ago when they'd discussed proposals? Hell, they'd been drunk. Why would Bucky remember…? Oh. "I thought this was cuter. Hang on." He nearly fell over as he rifled among the other packets of sweets. "Aha!" He threw the candy ring aside, and then held out a velvet box. "Okay. Here. So you know it's not some spur-of-the-moment, sugar-induced idea." He cracked open the box carefully, and Phil gulped when he saw the ring. "Marry me, Phil?"
"…Uh, okay?"
It was Gummi Worm Day, and I just couldn't resist it. Phil proposed earlier; it's only fair that Bucky get his chance.