Disclaimer: I don't own Batman, Superman or its characters.

...

"Kal-El."

The calling was nothing but a whisper, but the name and the familiar voice that uttered it resounded clearly for him, even in the middle of the usual chaos of the Daily Planet. It drew his attention away from the story he was supposed to be working on, focusing instead in hearing any further communications.

Clark was not sure why Bruce chose to call out to him instead of using their comm links, but there must be a reason for it. There was always a reason with Bruce.

He waited, but there was no sound from the billionaire after that, making Clark furrow his brow. He extended his hearing, searching for the familiar pattern of Bruce's heartbeat. The heartbeat was strong and steady, but it took him a bit longer than usual to find it, which meant Bruce wasn't in Gotham. The realization made Clark's frown deepen.

There was no news about Bruce Wayne leaving the country, and he hadn't mentioned any Batman-related business away from the city either. But, he wouldn't put it past Bruce to not say anything.

Still, he couldn't help but worry about him. What if he was in trouble?

A ball of paper bounced off his chest, making Clark blink and look up to see Lois sitting on the opposite desk, giving him an annoyed look.

"About time you pay attention, Smallville. What's up?"

Clark pushed his glasses up his nose. "Nothing. Everything it's fine."

Lois arched an eyebrow. "You sure about that?"

"Yeah," Clark replied even as he stood up from his chair abruptly, dropping his pen in the process. "I, uh. I have to go."

He hurried toward the elevator without waiting for an answer, not looking back even when he heard Lois calling after him. He had no idea what he would tell her once he returned, but he had something more important to worry about at the moment.

Not sure how long he would be gone, he chose to leave the Planet via the door rather than the rooftop of the building this time. He changed into his uniform in the first empty alley he found and flew up, following the sound of Bruce's heartbeat as a beacon.

His worry only grew when he was led to fly over the Sahara Desert, hailing to a stop in midair in the Libyan territory. Still following Bruce's heartbeat, he found a strange large ship hidden behind the huge dunes of the desert.

It wasn't long before Clark found Bruce inside the ship, using his x-ray vision. He was unhurt, alone, and pacing around the small room he was in. What took Clark by surprise was the fact he was wearing a three-piece suit rather than Batman's cowl and cape.

What could aliens possibly want with a billionaire playboy? Sure, he had some power as owner of one of the biggest companies in the world, but the first target for any aliens invading Earth should be a president or several.

After taking a look around the ship, Clark broke in and headed straight to the room Bruce was in. He heard an alarm go off but didn't stop until he reached his friend. Before Clark could ask him anything, one of the aliens in the ship entered the room, watching him with big, oval-shaped purple eyes and dressed in a large blue robe that pooled at its feet.

He had a humanoid form (or at least Clark thought it was a male) with two arms, legs and eyes, but that's where the similarities ended. The alien's smooth skin was a lilac tone, his frame thinner and taller than a human's; his legs, arms, and fingers slim and large. He had two horns on top of his head, perhaps about the size of a human's palm, and his nose was missing.

Still, Clark had to admit that as far as aliens went, this wasn't the most strange or threatening he had ever met.

"Hello," Clark greeted politely, only then wondering how he was going to communicate with the aliens exactly. He should have thought to bring J'onn with him, or call him once he made sure Bruce was okay.

"You. Out. He. Mine. Mate."

Clark blinked, honestly surprised by the broken, strangely accented English spoken by the alien as he pointed to where Bruce was standing. He flickered his gaze in Bruce's direction for a second, before looking back at the lilac form. "You- you think Mr. Wayne is your mate?"

The alien's eyes turned darker. "Mine. Mate."

"But that's impossible. You're both from different species." Clark countered with a furrowed brow. Surely the alien understood that much, right?

"Mine."

Clark chose to remain silent for a moment. There was no reason to antagonize the alien if it wasn't needed, so he changed tactics. "Why do you think Mr. Wayne is your mate?"

"He. Mark. Mine." The alien replied in the same broken English, pointing to the right side of his abdomen.

"You have a mark ...?"

The alien made a strange beeping noise before pulling open his robe (it had a special opening where the alien had been pointing) and showed him the mark he was referring to. It was a thin, mostly straight line on the right side of his abdomen, six or seven inches long, the skin a slightly darker tone there.

"He. Mark." The alien added, pointing slim, long fingers in Bruce's direction. Clark turned to him, curious.

Bruce rolled his eyes, but popped the buttons of his shirt open anyway, pulling the white cloth aside to show a line of puckered skin on the right side of his abdomen, caused by a five or six inches long cut a few years old. It looked strangely similar to the alien's mark.

Clark would have laughed at the absurdity of the situation if he wasn't sure neither Bruce nor the alien would take that reaction well. Instead, he tried to think of a way to convince the alien Bruce wasn't his soulmate in spite of the "evidence".

"Is it a birthmark?" The alien's eyes only made a strange rolling motion, so Clark clarified, "Your mark. Were you born with it? You have had it for a long time?"

"Mark. Old. I. Small."

Clark nodded eagerly. "The mark you see in Mr. Wayne's body is not an old one, and it is, in fact, a scar not a soul mark. You know what a scar is, right?" He tried to reason. "A scar it's a mark left by a healed wound. He was injured, hurt, and that's why he has that mark."

"I. Fight. Hurt. Him." The alien snarled (that was the only way he could think to describe his reaction, even if it was far from looking like a human's snarl) as he dropped into a fighting stance.

"No, no. That's not-" Clark started, hands raised in an appeasing manner. "It was an accident, okay? I didn't hurt him. No one hurt him. And he's fine now."

The alien made the same beeping sound again but didn't drop the stance.

"Can you stop that already?" Bruce snapped, obviously tired of the two aliens discussing things around him. "I have spent hours trying to explain all that to our strange alien friend, but he doesn't seem to understand any of it. He still insists we're soulmates."

Clark watched the alien relax his stance, his eyes turning a soft light purple tone, almost lilac again as he looked adoringly at Bruce. It wasn't going to be easy to get rid of him.

He cleared his throat. "I don't believe Mr. Wayne is your soulmate, but even if he were," Clark added before the alien could say anything. "You can't take him against his will. There are laws here on Earth that state both parties have to consent to form a bond."

"Mine. Mate." He replied simply, making again that strange beeping noise that was starting to get on Clark's nerves.

"For fuck's sake," Bruce muttered only loud enough for Clark to hear (if the other aliens didn't have enhanced hearing, that is) before turning to the enthralled alien. "I can't be your soulmate because I already have a mate.

"Kal is my soulmate." Bruce declared with a nod to where he stood.

Clark's head snapped in Bruce's direction, eyes wide and mouth slightly open in shock. He covered his surprise quickly, thankful the alien was too preoccupied watching Bruce to notice his reaction. He had no idea how Bruce was going to pull this off. Somehow, he didn't think his word was going to be enough to convince his admirer.

The alien's horns folded almost like dog ears, and fine green lines appeared all over his body. "You. Negative."

Without a word, Bruce reached to open the button of his pants, lowering them slightly to show the alien his left hip bone, and the familiar series of Kryptonian symbols printed on it.

Clark was unable to look away, his gaze fixed on the dark symbols contrasting with Bruce's light skin. How was this even possible?

Bruce knew Kryptonian, of course, but Clark couldn't imagine why he would even consider tattooing Kryptonian symbols on his body, let alone trust anyone to do it. He couldn't even detect traces of any kind of earthly ink in the skin, but any other explanation was just impossible.

"Kal," The familiar growl of his name finally managed to drag his attention away from the mark as he met Bruce's icy blue eyes. "Show him yours."

It wasn't surprising that Bruce knew about his own mark, not really. Still, it took Clark a moment to comply, slowly reaching to uncover his own hip bone, showing his own set of Kryptonian symbols on his skin.

Rather than being annoyed by the sound of the alien's strange beeping noise, this time, Clark was grateful because it helped him focus back on what was happening around him.

"Come here," Bruce beckoned him. Clark looked back at the alien to make sure he wasn't going to attack him for getting close before floating toward him. Bruce met his eyes briefly with an opaque look before reaching out, letting the pads of his fingers ghost over the mark on Clark's skin, making him shiver. The light touch, skin on skin, was enough to send ripples of electricity through every cell in his body.

Under the heavy weight of his gaze, and after receiving an almost unperceptive nod from Bruce, Clark barely stopped the shaking of his hand as he reached to touch the other man. The sound of the billionaire's accelerated heartbeat filled his ears as he held his breath, watching the dark mark on Bruce's skin turn a soft golden tint under his fingertips.

Distractedly, Clark noticed the same thing happened to his own mark.

A sound, like the howling of a wounded animal, made Clark look back at the alien. There was no murderous rage in the lilac eyes, and he looked sickened more than ready to attack him, so Clark let out a breath and allowed himself to relax slightly.

Clark was flying away slowly, holding Bruce carefully in his arms. Other than Bruce's demand to stay until the alien ship was gone and the usual disagreement about the details for the flight back, they hadn't exchanged a single word after being let out of the ship.

The alien had been surprisingly amiable if dispirited and miserable once Bruce's bond with someone else had been proved, taking the rejection with aplomb. They were allowed to leave after some sort of quick and simple alien ceremony. The lilac creature (whose name Clark just realized he hadn't learned) had touched one of his cheeks to Bruce's own in a reverent manner, one of his slim hands touching Bruce's shoulder and making Bruce do the same while he muttered in a strange language for close to five minutes.

In contrast, Clark received only a single pat on the forehead that lasted a few seconds in farewell before they were escorted out.

"This doesn't have to change anything," Bruce's voice resounded over the sound of the wind, breaking the silence they had been flying in as they left the ocean behind.

"Of course it changes everything! We're soulmates!" Clark shouted, looking down at the man in his arms. Much to Bruce's annoyance, Clark was carrying him bridal style- the most efficient and safer way for him to carry someone for a prolonged period of time. Bruce had glared and huffed, but in the end had let him do it.

Clark cleared his throat, looking ahead. "How long have you known?"

There was a pause. "Since you invited me to the Fortress the first time. I recognized the Kryptonian symbols as soon as I saw them."

Three years. Bruce's first visit to the Fortress had been three years ago. His blue eyes alight with wonder and interest as he took in every corner of the crystalline structure. He loved the Fortress's computer system (after Clark had turned it into English so he could understand it). And he hated Krypto. Or, at least, that's what he said, though Clark wasn't convinced.

"Is that why you wanted to learn Kryptonian? To translate your mark?" Bruce had been determinate to learn the complex alien language, and Clark had been delighted by the possibility of having someone to talk to.

"That was part of it, yes, but I would have wanted to learn to speak it even without it. It's a great tactical advantage," Bruce added simply.

They were already flying over the country, so Clark was flying as high and fast as he could while carrying someone. Or, perhaps not as fast as he could. He was maintaining a deliberately slower pace so they could keep talking. Bruce must have noticed already, but he said nothing.

He wet his lips. "Why didn't you say something?"

Even cramped up in his arms, Bruce still managed to shrug smoothly. "I thought you knew."

"I didn't."

The corner of Bruce's lip curled up wryly. "I granted as much." Dark eyebrows knitted together above sharp blue eyes as Bruce turned to meet his gaze. "But, didn't you ever feel it?"

It. Clark knew perfectly what 'it' meant. The way he always felt drawn to Bruce's side, as if an invisible thread was pulling him. The way just being around Bruce made him feel content. The warm, happy feeling when he saw Bruce smile or even laugh. The sickening worry that weighed inside of him whenever Bruce was hurt or in danger. That small burst of emotions he thought he could sense sometimes when Bruce wasn't as careful guarding them.

Everything.

"I did. I just- I didn't know what it was." Bruce sent an incredulous look his way. "My whole planet was destroyed; every person that lived in it gone. I just didn't want to learn about something I would never experiment in my life." Clark shook his head. "A bond with a human was a notion that had never even crossed my mind."

Bruce gave a curt nod but said nothing. Clark remained silent as well because Bruce had this look on his face; the look that said there was something he felt the urge to say, but wasn't sure if he should, or if he was ready to share it. Clark waited for him. Always.

"When I was young, my mother used to order or buy antique books from all around the world. There was a little bookstore downtown we visited together sometimes, or she would return from her trips with a stack of books," Bruce was looking away from him, his voice soft. "We would huddle together in the library or my room and look through them, trying to find the language the symbols of my mark came from.

"We never found it, of course, and I stopped looking." The reason he stopped looking was loud and clear without being spoken.

Clark said nothing, simply met Bruce's eyes briefly, trying to cover his gratitude and happiness with a single look. He felt a warm and fluttery feeling spreading inside him; the same he always felt when Bruce chose to share with him a little glimpse of the real him.

They were flying over Gotham when Bruce spoke again, "I can't believe you never noticed the mark."

"How was I supposed to do that?"

"You've seen me naked, or at least half-naked, plenty of times," Bruce pointed out, a dark eyebrow arched.

"I- What?"

"In the shower of the Watchtower, in the med bay, even in the cave."

"Yes, well," Clark started, still feeling the heat on his cheek. Thank Rao Kryptonian blushes weren't as evident as humans'. "I have more important things to worry about when you're hurt that ogling you."

"So, that means you have never peeked while we're showering in the Watchtower at the same time?" Bruce asked with a sly twitch of his lip.

"Of course not!"

Bruce snorted, "You're such a boy scout."

There was a pause in their conversation as they reached Wayne Manor. By Bruce's directions, Clark flew over to land on the balcony of the billionaire's bedroom. With both feet firmly planted down on the floor, Bruce reached to straighten his suit.

"Wait. Does that mean you have?"

"What," Bruce asked without looking back.

"Peeked."

Bruce did turn then. "Of course I have. And I doubt there's anyone in the League who hasn't done the same, at least once."

"Thanks for telling me that," Clark replied dryly. "I don't think I would be able to meet anyone's eyes for a while."

"Please," He scoffed. "As if you've never watched yourself in a mirror. You can't blame others for being curious about an alien that looks the way you do."

"Is that your complicated way of saying you think I'm handsome?"

"That's not what I said." Bruce snapped, a light blush rising to his cheeks. It made Clark want to kiss him. More than usual, anyway. "I only meant that by human standards, you're physically ... perfect. It's only natural that people would feel tempted to look."

Clark couldn't resist it anymore. He used his super speed to close the short distance between them, but still gave Bruce a couple of seconds to stop him before kissing him; his lips moving against Bruce's in a soft but firm kiss that soon turned heated.

Bruce took him by surprise when he deepened the kiss; hungry tongue parting his lips before sliding inside, stroking and pushing. Their bodies were soon pressed together; Bruce's hand buried in his hair while Clark's was placed firmly on his lower back, pressing the other man's body impossibly closer to his own.

"Now what?" Clark asked, sweeping his tongue over his upper lip as they pulled away. Bruce's cheeks were flushed, his blue eyes smoldering, and lips bruised and damp. It took all of Clark's restrict not to kiss him again.

"Now you educate yourself," Bruce replied, just barely out of breath. "I can't believe I know more about your alien culture than you do."

Clark smiled brightly. "And then?"

"Then," Bruce said slowly, leaning closer again until their lips were almost touching. "We'll see what happens," He murmured before letting their lips met again.

Heart thundering in his chest, Clark relished every second of that kiss just as much as the first. He just couldn't get enough Bruce, and it was almost as if he couldn't get enough of Clark too.

It was over all too soon once again, and he started missing the feel of Bruce's lips against his own as soon as he broke the kiss.

"Don't you have a job to get back to?" Bruce asked finally.

"I guess I do," He agreed with a smile, not looking away from Bruce's eyes dark with lust.

Clark used his super speed to plant a quick kiss on Bruce's lips before flying away. He didn't look back. He knew he wouldn't be able to leave if he did.

Still, he kept smiling all the way to Metropolis.

...

a/n: I mentioned before that I love this trope, right? So of course I have to give it another go. And a less angsty and sad one at that. I hope you enjoyed it! And please, don't look too closely at my alien. I have no idea what I was doing with him. He was just a plot device.

English is not my native language, so any tips or corrections are welcome.