Thanks to the seahorses for giving me something to research so that I could make this believable. (fyi, this is not a direct mirror of their reproductive process, so don't use this to study for your biology exam, or anything.)

Fun fact: The "penis" of female seahorses is called an ovipositor.

Clark is a Seahorse

Clark sat at his desk doing breathing exercises and rubbing his palms against his knees. He had managed to keep his composure and concentration this far in the day, but now it was too much to handle. His heart was beating in his ears, as was Lois's, which was several feet behind him. It was so loud and wet, and he could smell her. He wanted to fly over and grab her and…

He bit his lip and glanced around. If he got up and walked to the bathroom, would anyone see the erection in his brown corduroys? He hoped they would keep their eyes on their work. He stood up and strode to the men's room. A scan with his x-ray vision confirmed that no was one inside. He entered a stall, locked the door, and stood in front of the toilet.

He pulled his dick out and started yanking it unceremoniously. His thigh muscles contracted, and he stifled a grunt. After about a minute, he was ready to come, but the door opened. Three men walked in, and he froze. If he continued, they would undoubtedly hear him. He hoped they couldn't see his feet under the door. They chatted as they used the urinals, then washed their hands. The sound of the water rushing was loud enough, so he started again. He clenched his teeth as his hips lurched, and semen squirted into the toilet. He quickly fixed his pants and flushed, then opened the stall door and walked over to the sink.

"Hey, Kent."

"Hey."

''''''''''''''''''''''''''''''''''''''

Lois stood up and shouldered her purse.

"Ready," she announced.

Clark smiled, and they headed out to lunch.

"Are you alright?" she said under her breath.

"Yeah," he mumbled.

She had seen him bolt to the bathroom earlier. She knew what was happening to him. He had explained it to her before it started. It was a peculiar characteristic of Kryptonian physiology that the males went into heat. She thought that only happened to female mammals, but he explained that Kryptonian males were the ones who bore the children, like seahorses on Earth. The concept was incredibly bizarre to her, but she took it in stride. Before they started dating, she had prepared herself for the possibility that some of the sexual things were going to be different.

They reached the lobby of the Planet. She grabbed his arm to stop him and stood on her tiptoes. He leaned down.

"We should do it now," she whispered in his ear.

He blushed.

"I just dealt with it."

"You barely made it 6 hours. You'll need to do it again before the day is out."

He swallowed and glanced around rapidly.

"Where?"

"There's a supply room over there."

She pulled him over and tried the door. It was open.

"Aren't these usually locked?" he said nervously, even as he followed her in, "The custodian's probably coming back soon."

"This guy doesn't lock it during his shift. I know because I've had meetings in here before."

He frowned quizzically.

"You meet people in a supply closet?"

She shook her head and undid his pants.

"If you don't want to do this, just say so."

"I never said that."

She smirked and dropped to her knees. She reached into his boxers and pulled out his semi-hard dick. She held it in her right hand and cradled his balls in the other as she kissed the base. She heard his breaths hissing out above her. He was a patient lover, but he was in a period of sexual frenzy right now, so she wouldn't torture him. She licked the pink tip, then slid her mouth onto him. Clark made a low noise in the back of his throat and mumbled something. Her mouth watered, and she sucked her cheeks in and started moving her head back and forth.

After a minute, she took him deeper, till his tip reached the back of her throat. Her tongue slid against the underside. He groaned and gripped her shoulder. She pulled back, sucking the excess saliva off as each slick inch emerged from her mouth. When the tip was the only thing left, she sucked harshly. His legs trembled.

"Agh!" he groaned and leaned over her, forcing a couple inches back into her mouth.

His warm, salty cum coated the back of her tongue, and she felt some of it trickle down her throat. She swallowed and sucked till he leaned back, and his head hit the door. She kissed the tip and tucked his dick back inside his underwear. He zipped his pants up and buckled his belt, then sunk to his knees. Reaching under her skirt, he pulled her panties down. He wrapped his left arm around her to pull her against him, slipped two fingers into her, and stroked them in and out while rubbing his thumb against her clit. She rocked her hips into his touch and stifled her moans against his lips. They kissed sloppily until she came with a muffled cry.

He pulled his fingers out and sucked them, then reached down again to scoop up more of the fluid. He did so repeatedly till she was as dry as possible. Then, he pulled her panties back up and lifted her to her feet. She slumped against his chest and kissed him again. He grinned and opened the door.

"How much time is left in lunch?" he asked, "I'm starving."

'''''''''''''''''''''''''''''''''

Clark lay on his left side in their bed with a towel spread beneath him. He held his right leg up to his chest and panted as he strenuously worked a metal dildo in and out of himself. His eyes were half-hooded, and he stared, unseeing, at the wall. It was difficult to maintain a rapid pace when his body was experiencing such intense sensations. He thought about Lois, imagined her breasts swaying as she plowed into him with a strap-on. They had sex before she left to go to the store, but he was getting hard again. It usually took her about an hour to return, and he was trying to finish before then.

He clenched his muscles around the dildo and yelped, body jolting, very nearly climaxing. He pumped the long object as fast as he could. His heartbeat thundered in his ears, his eyes squeezed shut, and he moaned loudly through an open mouth as he teetered on the precipice of ecstasy.

"Clark?"

His eyes flew open, and he saw Lois standing in the hallway, staring with a flabbergasted expression. He gawked at her, then yanked the dildo out and sat up inhumanely fast. How dead was he to the world that he didn't hear her coming up?

"Uh," he said as what felt like all the blood in his body rushed to his face, "I…This…"

"Are you…?" she began.

She was blushing, as well.

"I –" he tried again, but he didn't know what to say.

"Is that a dildo?" she asked, glancing where he was hiding it behind him.

"Uh…yeah."

"Do you…do you do this whenever I'm not around?"

He took a deep breath and glanced away.

"Lois, I didn't tell you everything about Kryptonian sex," he paused, "There's two parts to it. The first is the male fertilizing the egg, and the second part is her…depositing it."

Understanding slowly dawned on her.

"You mean Kryptonian females…have penises?"

"Something like it, yeah."

"I should've figured. So…you need that, too."

"Yeah."

"Why didn't you just tell me?"

"I was going to, eventually, I just -"

"It's ok," she said, smiling as she stepped into the room.

She stripped and climbed onto the bed beside him. She took the dildo from him, held it in both hands, and examined it.

"I've never used one of these on someone else before."

She glanced up at him.

"Do you want to lie down again?"

He lay on his back, and she came around to kneel between his legs. He spread them and lifted up his knees. He was still blushing, and his dick was fully erect. She pressed the tip of the dildo to his anus and looked up at him. He nodded, and she sunk it in. His hips jerked, and she stopped.

"More," he gasped, and she grinned as she buried inch after inch in him, until there were about 9 inches inside.

"Is that good?"

"Uh-huh."

His eyes were glazed over. She slowly dragged the dildo out several inches, then pushed it back in. He was tight, but spread wide enough that the movement wasn't difficult. She braced her left hand on his hip bone as she sped up. His hands clutched the sheets, and he stared at her. She stared at his dick, the tip of which was a warm, dark pink.

"Sorry for interrupting you," she breathed, "But then again, we wouldn't be here."

His legs spread wider, and he sighed. A couple seconds later, he started moaning. Every breath she forced out of him was accompanied by a high-pitched moan that sounded almost like whining. The sight of him like this – anus spreading for her, hairy chest heaving, quads bunching, dick flushed and swollen, nipples pursed, and muscular neck flexing as he gasped and swallowed – was enough to make her salivate. Her nipples pinched painfully, and her clit throbbed. She thrust faster and harder, and he could only breath in gasps occasionally punctuated by yells. He bit his lip and looked down helplessly. His legs drew up more. A strangled groan fell from behind his teeth, and he tilted his head back. His thighs pressed to her sides, and his back arched off the bed.

She couldn't resist anymore, so she grabbed his dick with her free hand and rubbed her thumb against the underside of the tip. He practically gagged, then made a desperate noise behind his teeth. He released a string of sounds, a couple of which she thought were attempts at her name.

Finally, his hips lifted up, and he screamed. A white, viscous substance leaked out of his tip in thick beads. Without thinking, she ducked her head and sucked them up. They tasted watery. Clark continued to moan and shudder. His legs squeezed against her sides, but not hard enough to hurt. She forced herself to pull her lips away since she didn't know if she would be able to stop tasting him once she started. He sank down onto the mattress again, legs falling open. She pulled the dildo out slowly, laid it between his legs, and massaged his inner thighs. Once his breathing evened out, he opened his eyes and looked down at her.

"Thank you."

"No problem," she said, smiling.

He looked hesitant for a moment, then said, "Can we do it again?"

"Sure…You mean right now?"

"Yeah."

She was surprised he still had the stamina, but then reminded herself that he was Superman. She slid the dildo inside him again and wrapped her left arm around his thigh. His expression was blissful as she fucked him. She wondered if he wanted her on his dick as much as she did. She was going to have to start rubbing her clit soon. Luckily, she didn't have to wait long. In a matter of minutes, he was crying out her name and dripping on himself.

When he emerged from the haze of his orgasm, he swallowed and said meekly, "Again?"

Her mouth fell open. She had no idea he was this much of a slut.

"Wow. Ok. Do you want to change position?"

He got on his hands and knees, and she knelt behind him. Her arm was getting tired, so she had to do it slower, but she made sure to press against his prostate. She knew when she hit it because of the guttural noises he made. He rocked his hips towards her, which helped as well. She couldn't ignore her clit anymore, so she slipped a finger inside herself, withdrew it, and rubbed the needy bulb. Her lips parted and trembled, as did her thighs. Her cheeks flushed, and she couldn't help whimpering. She imagined grabbing his swollen cock and bumping the hot tip against her oversensitive mound. She moaned, and her eyes drifted closed. She listened to their panting as she tried to re-focus on what her arm was doing.

When she opened her eyes again, she saw that his head was ducked like he was looking between his legs. She realized that he was watching her masturbate. A rush of blood went straight to her crotch. She gasped as she rubbed herself with her two longest fingers, letting them slip between her sopping wet labia and trail the fluid up to her clit.

"Oh, God," Clark groaned thickly.

Her moans became uncontrollable, and he started thrusting himself even more forcefully onto the dildo. He came before her, not even making a noise this time as his body went rigid. He was wracked with shudders and collapsed onto the bed, the dildo coming out with a pop. She let it fall from her hand as she focused all her attention on orgasming. She rubbed hard, hips jerking, until she tensed and cried out. She panted with her face upturned as she came down from the high.

He hadn't moved while she was dealing with herself. She clambered to the side and pushed against him, trying to get him to roll over onto his back. He weakly obliged her. There was a small wet spot where he had been lying before. He was clearly spent, but she wanted his dick; and, besides, he wouldn't have to do any work. She leaned over, grabbed the base, and sucked the tip. She loved the way the thick member felt in her lips. She ran the top of her tongue over it, then the underside. It was so warm and tasted like his prostate milk. Clark didn't make any noise, even when she started deep-throating him. She supposed he didn't have the energy anymore. She wondered if overstimulation was painful for him. She glanced up. His eyes were closed, and he looked serene. She pulled back anyway and crawled over to the bedside table. She took out a condom, crawled back, and straddled his hips. He opened his eyes.

"I know this is out of order," she muttered as she rolled it on.

She mounted him and rocked her hips back and forth, then lay down, wrapped her arms around his neck, and kissed him. He wasn't very responsive. After a minute, she pulled away and ceased the movement of her hips.

"I didn't break you, did I?"

To her relief, he grinned.

"I'm sorry. I'm just worn out. If I'm exhausted, then I can last longer before needing to do this again."

"I see. Should I keep going, then?"

"Yes, please."

They kissed, and he reciprocated more energetically this time. He rested his hands on her back, and she started humping him again. They came at the same time, her gasping and whimpering, and him grunting weakly. She sat up and slipped off of him, then tossed the condom down with the dildo and collapsed against his side.

Throwing her arm over him, she sighed, "Now you can sleep."

He kissed her forehead.

"Thank you, love."

"You're welcome," she mumbled.