This is just a little idea I came up with. One-shot, and completely random.
Neville lay on his bed, and stared at the ceiling. In his right hand, he held his mother's ring, which he planned to give to Luna when he proposed to her. "If I propose to her," he thought. The boy had tried multiple times to ask for the beautiful girl's hand, but had flubbed up each attempt. He knew he would have to do it soon, or it may be too late.
A small fireplace in the corner was bright with flames. Floo powder was waiting in a jar on the mantel. "Okay, Longbottom," Neville said aloud, "Here's what's gonna happen. Your gonna get your butt off this bed, Floo over to her house, and propose. Simple as that." His cowardly side answered back, "What if…." Brave Neville stood up and declared, "The time for ifs is over."
Luna was sitting at the kitchen table when Neville walked out of her fireplace. "Oh, hi, Neville!" Luna cried when she saw him, running over to hug him. They had been going out for months now, and still the sight of her wonderful smile knocked him off his feet. Literally. The two were flat on the floor in moments, Luna giggling with glee and Neville chuckling nervously.
As they got up, Luna looked at her boyfriend quizzically. "Something is bothering you." she told him, taking the seat across from him. She looked into his deep blue eyes, and he replied."Yeah. I want to do something really important, but I don't think I'm, uh, brave enough." Neville fumbled his words, trying not to make a fool of himself. "Luna replied in her usual way; quickly. " Well, Frank Jones once said, 'Bravery is being the only one who knows you're afraid.' He was American, you know."
Neville looked lovingly at Luna, and said, "Luna, marry me," rather surprisingly, especially to both sides of himself. Luna smiled brightly and said, "I thought you would never ask."
And the kiss they shared beat out the kiss from The Princess Bride for most beautiful kiss of all time.