Duo and Heero share a conversation during the repair of Wing ZERO. No specific point during the timeline.
Duo leaned over the railing in the well-hidden hangar as Heero patched up his gundam. "Man, do you ever take a break!?" He emphasized the "ever," watching Heero visibly twitch at the intrusion. "You're ignoring me, aren't you? So co~ld!"
"Why don't you make yourself useful and go annoy someone else for once?" The agitation was evident in Heero's voice as he pulled the blue control panel off and began to lace wires back into their places, replacing what needed it and patching what he could. Duo felt a bit shaken to have gotten to his stoic friend so much, but they were all on edge after the last few battles.
Duo, however was determined. "What's crawled up YOUR ass and died? I mean, man. Seriously."
Heero was at this point just shutting him out and he continued to work, but Duo was, as previously stated, determined, and was down on the floor at his side in a minute. Heero frowned at Duo's trotting up, which to him sounded like a galloping of a horse, but that was just his heightened senses talking.
"And I think that you're just nervous cause you don't know what to do with Relena. I mean, god, man. Have you ever even kissed a girl before?"
Heero flinched a bit at this, slowing a bit in his repair job. That had stuck a nerve, Duo noticed. He was now torn between continuing in his vein or letting Heero go with that. His thinking left an awkward silence.
He twiddled his thumbs, realizing that maybe he had gone a bit too far. He was surprised, though, when Heero started with a simple "Yes."
Duo forgot all previous remorse. He just had to hear this. "Yeah? Yeah? Man, come on! Juicy details?"
Heero's gaze fell as he brought up the old memories. "It was when I had just started to actually be taken out on missions. She was... I thought she was," he paused for a moment, trying to find the right word, "attractive. She was my age. I'd heard about 'dating' and I hadn't realized that my lifestyle would prevent me from forming lasting relationships."
"This is gonna be a sad one, isn't it?" Duo asked, doubtful as to whether or not he would like the outcome of this.
Heero met his gaze. "Life is pain. Did you want to know the rest of it?"
Duo nodded, albeit reluctantly. He never liked tragedies, but he did want to know more about Heero. Since, they were working together and all. Made sense to him, anyway.
"We got to know each other for a few days, then I had to leave the area, and we forgot each other. It was later that I was assigned to demolish a hidden armory in that general area. She was caught in the crossfire. She remembered me, and she asked for one thing before she died. And that was my first kiss." Heero had never been one to embellish on the details.
"Dude... morbid?" Duo leaned back against the foot of Wing ZERO.
"She smelled like peony."
Duo did a double-take, "Random much?"
"It was different from the oil, grease, sweat, and blood I was used to."
With that, he turned back to his gundam, screwing something into a panel. Duo decided that he would leave Heero to his musings.
And with that, things went on as usual. Back to what they had always been, but Duo tucked that bit of information away. He knew one more thing about the so-called "perfect soldier" and that wasn't to be taken lightly.