Lucy found it dropped on the floor where Natsu and Gray had been fighting. It was a metal band, large enough for her to fit maybe three fingers through, with a ribbon wrapped around it. Most likely, it was some odd, voodoo trinket that Juvia had slipped into Gray's pocket to enchant him into loving her.
It had only been a few weeks since Juvia had finally dropped her 'love rival' shtick, and Lucy didn't feel like regaining that label by making it look like she was trying to keep Gray from loving Juvia. She gathered up the clothes Gray had lost in the fight and went to his table.
"You dropped this," she told him.
Gray looked at Lucy, gasped, then looked down at himself. "When did I lose all of that?"
"About five minutes ago." She set the clothes and the metal band on the table. "Here."
Gray pulled his shirt and jacket back on. He grabbed his pants too, but somehow they didn't make it from his hands to his legs. He picked up the metal band next, and examined it. "I think this is Natsu's."
"Are you sure?"
"Yeah. Look." He showed her the point where the ribbon had been tied. "These are his crappy knots."
Choosing not to comment on the fact that Gray could recognize something so minor as the type of knots Natsu tied, Lucy took the ring and walked over to the job board, where Natsu and Happy were discussing whether or not Lucy would want to go with them on a job to capture a lava monster.
"No," she told them.
Natsu turned around, grinning when he saw she was there. "Come on, Luce. It pays pretty high. You still need rent money for the month, don't you?"
"Still not gonna happen. Here." She held the metal band up. "Is this yours? Somebody dropped it during the fight earlier."
Natsu blushed and muttered something.
"What?"
"It's yours."
"No it's not."
"Yeah it is. Look."
Natsu took the metal band from Lucy's hand and slid it over her middle, ring, and pinky finger. "See? I'd been working up the nerve to give it to you."
Lucy held her hand up, inspecting the metal band with a blank look.
"It's a key ring," Natsu explained.
"I have a ring for my keys already. Why are you giving me this?"
"Well, Gildartz said that when you want to be with a girl forever, you give her a ring."
STA: Originally written for a prompt blog on tumblr. The prompt given was Nalu marriage proposal.