For those of you confused: ABO is shorthand for Alpha/Beta/Omega. Think wolf packs and their dynamic if that helps.

Tsuna is an Omega, but because he wasn't raised in that world he doesn't have the "usual" behavioral patterns attributed to them...I/E overly submissive. He's more inclined to punch an Alpha in the face and rob them blind rather than allow them to dominate him.

It took two long, agonizing (in Fon's opinion) weeks before Natsu relaxed enough around him to let him into his apartment. Which was surprisingly well kept and had quite a few familiar spices. Best of all the roof was relatively open enough to practice martial arts and to give Natsu some actual training.

Once Natsu got used to his presence, Fon was delighted to find that the other male was quite the cuddler.

More than that, Natsu was rather open to the idea of training...so long as it didn't conflict with his gymnastic classes, which was the closest thing he had been able to find. The only reason he could even enjoy that much was because the class in question was firmly an "Omega-Only" one, and they had strict rules about Alphas or Betas trying to interrupt.

Most of the Omegas in that class were from abusive relationships just trying to regain themselves before it got to be too much. Having someone like Tsuna around was helping immensely and they were all very empathetic about the annoyance of grabby Alphas.

(The fact Tsuna just so happened to beat the crap out of a few of the more unpleasant Alphas trying to reassert their dominance on their former Omega partners and then robbed them was the main reason why he never had to pay for lessons.)

Tsuna POV

His life was officially weird, but at least if he had to attract a member of the future Arcobaleno, it was one that he could relax and trust.

Fon was very straightforward and much easier to deal with than say, Reborn or Viper. Though he was a bit of a perfectionist when it came to martial arts, Tsuna openly enjoyed those lessons so that was okay. Even if Fon's hands had a rather odd habit of straying to places that made him shiver.

Which he suspected was less "straying" and more "deliberate". Considering his lack of a dating life, Tsuna was all too happy to turn a blind eye to that so long as Fon never took it too far without permission first. A fact Fon was quick to pick up on and accepted.

So yeah, his life was finally starting to look somewhere in the neighborhood of tolerable, which was why Tsuna was openly looking for the other shoe to drop.

And did it ever. Not more than a month after Fon and Tsuna had started to settle into what many would consider an "Alpha-Omega" relationship, Tsuna ran headfirst into yet another scent that caught his attention and made him follow it without knowing.

In retrospect, the scent should have tipped him off as to who he would find. Who else would smell of gunpowder, lizard scales, sun-kissed skin, coffee and that particular brand of chocolate he knew Reborn loved, but would deny any addiction to if asked?

At least this time he was able to cover the reason for why he entered that particular bar easily enough, after Fon elaborated on why he had taken such an intense interest in him after he made the mistake of mentioning it was his scent that drew Tsuna to him.

To be fair, he highly doubted his mother (if he had been born into this world) would have mentioned something like scent markers. She was always trying too hard to hide the pain she felt at the fact Iemitsu was never around and raising a kid as a single parent in a community oriented country like Japan. About the only reason she wasn't ostracized more was because of the fact Iemitsu actually married her and she had the wedding certificate to prove he had been born after the fact, well over nine months after the honeymoon was over.

Tsuna picked out a random bar stool away from Reborn and ordered the first thing that came to mind. He wasn't really in the mood for it, but he might as well have at least one drink.

So naturally he couldn't help the first reaction that happened when Reborn smirked, walked over to him and used a rather ridiculous pick-up line on him.

He choked a bit on his drink in disbelief.

"Excuse me?" he said baffled.

Because seriously, this was Reborn. A man notorious for having beautiful women (and the occasional guy from what he heard) falling in and out of his bed whenever he wanted it. Why the hell was he trying to pick someone like him up?

Reborn smirked at him, and Tsuna continued to stare at him in no little amount of incredulous confusion.

"I said would you like to spend the night at my place or yours?" he repeated.

Tsuna had to blink slowly at that.

"What on earth would make you think I'd even be interested in someone like you?" he said carefully. It was unlikely that Reborn would try to shoot him, but you could never tell with this chaotic pain in the ass.

Tsuna idly wondered if Reborn noticed the fact he was rapid-fire texting Fon for a rescue. As someone born in the age of smart phones, being able to text without looking at the phone in question was a pretty common skill.

Even if he only really got into it after he met his Guardians, he could still text on the flip-phone had on him that Fon gave him.

He could only feel relief when Fon came in, saw what was going on, and calmly walked up behind Tsuna and wrapped his arms around him.

"You should know better than to walk into strange bars," he commented, giving Reborn a Look.

Tsuna blushed at that, and was glad he wasn't drinking anything when Reborn smirked at them both and said "You know if you wanted a threesome you should have said so."

Fon had to roll his eyes as Tsuna sputtered at that.

He was relieved that he had already paid for his drink, because they were able to leave relatively quickly.

"So what really happened?" asked Fon seriously.

Tsuna groaned.

"Remember how I ran into you the first time, before you started stalking me?"

Fon blinked, before giving him an odd look.

"You have a very strange preference when it comes to Alphas."

"I didn't even realize I was following it until I reached the bar! And the only reason I went in was so that I knew who to avoid once I came to my senses!" protested Tsuna embarrassed. "At least I texted you the second I realized he had taken a strong interest in me. I doubt I could have dealt with him the way I usually do."

Fon hummed, pleased that Tsuna had texted him rather than attempt to fend off the World's Greatest Hit Man alone. And that he hadn't even thought of taking up the man's offer.

But still, it was very odd that Tsuna's preferences clearly ran towards the more dangerous individuals who could easily eat him up alive with far more experience than him.

How often could one find an Omega drawn to the scent trail of both Fon and Renato Sinclair, after all? And not be terrified at what lay at the end of it? Especially one as skittish and adorable as Tsuna?

Fon wanted to sigh...instead he smirked.

It seemed his little Omega kitten needed a reminder not to follow scent trails, though what were the odds that he would follow Renato's without thinking?

Tsuna wanted to curse. Out of all the things that annoyed him about this world, Omega Heats were one of the worst.

Fon however, looked anticipatory about the whole thing for obvious reasons.

Which was why Tsuna decided they needed to clear the air a bit, because he refused to start a relationship built on lies. Not after what it did to his mother.

"I think we need to have a talk," said Tsuna.

Fon paused, and looked at him with a serious expression.

"About?"

"How about us, and where we might go from here. As much fun as we've had, I really don't want to start calling you my boyfriend if there are certain secrets between us," said Tsuna bluntly.

Fon went still at that, before getting out some liquor. Somehow he had the feeling he would need it.

"Where do you want to start?" he asked.

Tsuna looked him dead in the eye and said "I know exactly who and what you are, and I've known from the second I first saw you in the clearing. I'm also aware of your position in the Triads and the fact you're the strongest Storm currently alive."

Tsuna could feel how tense Fon was hearing that. He was clearly worried Tsuna would leave him.

"To be fair, I've also kept a few things from you. Like the fact I'm technically part of a famiglia, though they aren't exactly aware of me at the moment and I would very much like to keep it that way."

As far as he could tell the only major difference between his world and this one was the whole secondary gender thing.

That, and the fact that Timoteo once hit upon him in a bar before he knocked the man's light's out in an alley and accidentally took the Vongola heir ring before he realized what it was pretty much confirmed he was still a 'bloodline Vongola'. Giotto had been very surprised to see him, as were the other Dons, though it took Tsuna three hours to finally stop swearing when he realized what happened.

His time was still engraved in the ring, after all, even across dimensions.

"Which one?" asked Fon, somewhat worried.

"Vongola. Long story short the Primo decided to retire to Japan rather than fight it out over succession because of his Mist, and he ended up remarrying there," said Tsuna. "He's my great-great-great grandfather, if that helps. Again, do not want them to know I even exist...it was a pain getting away from that nightmare and I have no intention of returning to it unless I absolutely have to."

Fon stared at him.

"I can get a verified history book if you like. I've heard repeatedly that I'm a dead ringer for him, save for the fact we have slightly different hair color and the fact I have more Asian features than he did," said Tsuna helpfully. "Though to be fair you could easily pass for a longer black haired Alaude, with Asian features."

"Who's Alaude?" asked Fon, unconsciously relaxing.

"Primo's Cloud Guardian and the original creator of CEDEF. Very much a classic cloud."

"So... you knew who I was the first day we met."

"I would have walked away if you hadn't spoken up. I had no intention of interrupting your meditation, or trying to drag you into my problems with Alphas. I just don't want my first real relationship to end up the same way my mother's marriage did."

Fon handed Tsuna a glass of strong liquor.

"What happened?"

"My father," Tsuna practically spat out the word, "Is an arrogant, narcissistic bastard who cared more about his famiglia and his job than he ever did about us. He would show up once or twice every couple of years, spend all of a week pretending he loved my mother to get her hopes up, then gallivant back off to Italy where he could cheat on her repeatedly with random women while she stayed at home raising me. I can't count the number of times I heard hear crying at night because he wasn't around and she was lonely. And the worst part? The bastard didn't even have the balls to tell her the truth. He gave her a lie that no one could believe about working construction in the South Pole and all the contact information he gave her was false."

Fon was silent.

"And you were worried I'd turn out like that?" he asked quietly.

Tsuna shook his head.

"No. I've just seen where a relationship built on lies and secrets can lead and I refuse to let mine follow the same pattern. I'd rather have honesty from the start before we think of making it a serious one."

Something in Fon relaxed at that. All his boyfriend was asking was for simple honesty, and he could accept that requirement. Especially since he had outright admitted to knowing about Flames and what Fon did already.

Fon took a long pull of his drink before pouring another.

"Well as you know I'm a neutral enforcer in the Triads, though not without effort. I can't count the number of times Skies have tried to pull me in and fail because of how strong I am, or because the Triads don't like having such a free agent like me. Though I must admit I'm surprised you already knew who I was before we had this talk," said Fon.

Tsuna smiled at him.

"I've dealt with far more annoying Elements than you. Just because you've killed people before and will likely do it again doesn't mean I have to be afraid of you. It only means I need to be there for you when you have a really, really crappy day and just need someone there to listen," said Tsuna.

"Is there anything else I need to know?"

"My name isn't actually Natsu. It's just an anagram of it...though to be fair I've come to hate my actual name considering how many people use this awful nickname I've had all throughout school."

Fon blinked, before mentally rearranging his boyfriend's name to make a guess at what it actually was.

"Your real name is Tsuna?" he asked smiling.

"Tsunayoshi, to be specific. I never liked being called a tuna much though, and it didn't help that I was called 'Dame-Tsuna' growing up by nearly everyone around me. I'd rather be Natsu."

Fon hugged him from behind.

"Would you rather I call you Tsuna or Natsu?"

"Natsu. The less I'm reminded of that nickname I had growing up the happier I'll be."

Fon felt openly relieved that his boyfriend suggested they have this talk, before they moved onto a more physical relationship. It was...nice...to have the air cleared between them before they got into anything serious, because it meant they could continue without worrying if the other party knew something that could ruin everything.

Fon happily cuddled Tsuna, pleased beyond belief that he didn't have to hide what he was or what he could do.

Tsuna had a rather wicked grin on his face.

"Just wait until you find out what my Flame type is," he said snickering.

Because if Fon's scent had lead Tsuna straight to him, then he had little doubt they would be compatible Flame wise. It didn't hurt that he had always felt a stronger 'connection' with the Arcobaleno than he ever had his own Guardians, save for Mukuro.