It had taken Hordak and Entrapta two days to prepare their first prototype. Due to long hours, the pair of lab partners had been too exhausted to begin the first round of experimentation right then. Instead, they had laid down on twin cots in Hordak's lab to sleep. A few hours later, a bot awoke them with the scheduled delivery of ration bars.

Once they had finished eating, Hordak felt the nerves of anticipation rise in his chest. "Are you ready to begin our first experimental trial?"

Entrapta swallowed the last of her food, then nodded. "I'm ready. Oooooooh, this is gonna be so much fun!"

Since it was necessary to ensure a disruption free environment, Hordak sent out the order that no one was to disturb him or Entrapta for the next hour. Not even Emily or Imp would be allowed to interrupt them.

Next, the two of them made their way to Entrapta's private bedchambers with the prototype. This was where Entrapta typically engaged with her sex bots. By keeping as many external variables unchanged, the two would be able to compare their experiment to previous data. Because Hordak had seen the room in videos so many times, it didn't occur to him until that moment that he'd never physically visited her bedchambers before.

The room was… quaint. Smaller than most rulers would typically fashion their most private sanctum to be, and still decorated like a nursery in some corners. Hordak suspected Entrapta had grown up using this room to sleep and declined to move into the master quarters when the opportunity first presented itself.

The only part of the room that seemed to be up to date was Entrapta's bed. She had fashioned it to have one large, firm mattress capable of supporting both herself and several bots. Lilac sheets and a deep purple comforter lay wrinkled off to one side, revealing Entrapta's preference for sleeping on the left side of the bed. Since Entrapta usually folded her hair into a pillow when resting, there were no pillows to be found anywhere in the room.

Entrapta plopped onto the side of her bed with enthusiasm, kicking off her shoes so aggressively that they hit the wall. Judging by the scuff marks on said wall, this was not the first time Entrapta had done such a thing.

Hordak watched in silence as Entrapta stripped all the clothes from her body. When she was nearly finished, Hordak removed his own tunic and shoes. As Hordak was now accustomed to sleeping in his armor, he saw no reason to take it off. Furthermore, the artificial penis connected to him through his armor. There was no natural port on his body capable of holding the device in place.

He held his breath as the brasserie and panties fell from Entrapta's curvaceous body. Her naked form was something Hordak had pored over hundreds of times as of late, yet seeing it in person was an experience of its own.

Hordak knew little about Etherian beauty standards. He knew not what females of his species had once looked like. Yet when he beheld all of Entrapta in person for the first time, he was convinced she was the most exquisitely crafted being in the known universe. The sweat on her brow, the drip of grease down her bosom, the muscles in her arms, legs, and neck supporting her through a long day's work. She was the perfect union of form and function, painted in pale cream skin and sweeping purple hair.

It was then that Hordak observed the other spots of hair on Entrapta's body. The hair gathered around her armpits and pubic area was darker and curlier than the hair on her head. Much like her eyebrows and lashes, it appeared to lack the dextrous function of her principal mane. Hordak had never observed Entrapta use her pubic hair to hold a sex toy in place, but he had privately wondered if she were capable of such a thing.

She watched him take her in with a nervous smile on her lips. When Hordak locked eyes with Entrapta, she asked, "are you ready to put it on?"

"I am." Hordak had spent the last several days psyching himself up for this moment. He wasn't going to allow any fears of the unknown to stop him now. He unsheathed the prototype from its carrying case, lined the device up in the space between his legs, and attached it to the nearest port on his armor.

Entrapta clapped when the device locked into place. "It fits perfectly! You look so good with a penis, Hordak!"

Hordak regarded the device with a fresh sense of curiosity. He hadn't yet turned the sensors on, but the weight between his legs was already a new experience. They had not created the device to be particularly heavy, but the technology within still ensured it was several pounds heavier than its biological counterpart would be. He shifted back and forth, device suspended in the air in the upright position.

"Will it be sufficiently flexible for our purposes tonight, Entrapta?"

She nodded. "It's better if the penis isn't floppy, actually. They're supposed to get hard and stay hard during sex."

This was it. They were ready to begin their first experiment. Not just with the device on Hordak's hips, but with intimate relations in general. Of all the new experiences, this one gave Hordak the most anxiety. The most excitement.

"Entrapta, I… I know your experience with robots is extensive. Have you ever had sex with an organic being before?"

"Nope! You're the first." Entrapta blushed. "This might make our early trials a bit more… error prone."

"All is well. We will correct any errors we make with repeated tests."

Entrapta reached out a tendril of hair to bring Hordak closer to her. She held his waist in her clutches, perching him in front of her as she sat sideways on the bed. Hordak bent down to her height, unsure what to do next.

"We… we shouldn't start penetration right away. I'm not lubricated yet."

"Ah, of course." In all of Entrapta's videos, the first several minutes were devoted to foreplay. Hordak leaned down to catch Entrapta's lips in a kiss. He bent his lips over his teeth to ensure he didn't catch her with his fangs.

She returned the kiss with additional force, pushing his lips out of the way to explore his mouth with her tongue. Hordak had never felt such a thing before. Too afraid of hurting her to fully reciprocate, he simply let Entrapta take the lead as their mouths exchanged fluids.

To steady himself, Hordak laid an arm on Entrapta's bare shoulder. He marveled at the softness and warmth of her skin, so unlike his own. His hand slid down to her breast, again careful not to catch her with his claws. For the first time in his life, Hordak regretted being designed to maim and kill. His sharp teeth and long claws made it difficult to express love for the woman beneath him.

Entrapta hummed with pleasure as he massaged her breast, breaking their kiss only to gasp for air. Yet Hordak didn't need air as often as Entrapta did, so when she pulled away, he shifted his kiss to her neck, seeking out her pulse points without biting too hard. Her soft moans reassured him that he was applying the appropriate amount of pressure.

"That's good," she breathed. "Keep… doing that."

Hordak brought his second hand over to clutch her waist to his. Entrapta's hair pulled him closer, pushing her chest against his chestplate. He felt her heart rate quicken over his armor, its sensors picking up every bit of movement. Next, her hands cupped around his neck, guiding Hordak's mouth to where she wanted it most.

Hordak let himself kiss every inch that Entrapta opened up to him, concerns about tonight completely forgotten. Never had he thought he could enjoy a physical experience so thoroughly. No kill had ever been as satisfying as the love they were making.

When his mouth reached Entrapta's navel, he used his hands to open her legs wider. Hordak was prepared for the sight of her wet private parts. What he wasn't prepared for was the thick, heady scent of arousal. He breathed deeply, driven giddy by the knowledge he'd brought Entrapta to this state. For the first time in his life, Hordak's eyes glowed bright purple.

He let his fingertips scrape over the labial folds, marveling at the slickness gathered around them. He rubbed her clitoris a few times, then asked. "Would you like to begin penetration?"

"Yeah…" Entrapta breathed. She fell back onto the mattress, leaving room for Hordak to assume a mounting position.

Hordak put one knee on the mattress, trying to hide his confusion. He lined his artificial penis up with Entrapta's preferred hole, then leaned forward slowly. When the tip of the device slid into her vagina, Entrapta gasped.

"Is that painful?"

"No! No, it feels good." Entrapta sighed. "I like the feeling of cold metal down there."

Hordak took her word for it. Careful not to stretch her too far at first, he slid their newest invention further in. When the tip bumped into Entrapta's cervix, Hordak could just barely feel the heat of Entrapta's thighs on his legs. So long was the artificial penis they'd fashioned for the night.

He slowly slid the device back out, watching Entrapta's face as he did. She seemed to enjoy the movement, so he pushed the penis back up to the point he'd had it several seconds ago. This time, Entrapta thrust her hips in turn with his, guiding him into a languid rhythm.

This part wasn't as enjoyable for Hordak as before had been. While he understood Entrapta was experiencing stimulation in the most sensitive nerve cluster on her body, there were significantly fewer stimuli coming in on Hordak's end. Instead of pondering the matter, Hordak focused on making Entrapta's experience the best he could, increasing the pace of his thrusts at her request.

A few moments later, Entrapta cried out. A thicker stream of fluids slid out of her hole and down her thighs. Orgasm.

Hordak breathed the scent of victory in. He felt more satisfaction in that moment than he had the first time he'd taken over the Fright Zone. More satisfaction than war and carnage had ever brought him before.

Before Hordak could express these sentiments with words, Entrapta's hair pulled him on top of her in the bed. Only his elbows and her hair kept Hordak's weight from crushing her smaller frame. She brought his mouth back to hers for a passionate kiss. Hordak kissed her back recklessly, eager for the sensations her body brought to his own.

It was the first time in Hordak's thirty-two years of life that he enjoyed having his body. Armor reduced his pain, but never had it brought him joy in this way. To know the woman he loved was capable of making him feel so whole… Hordak wished their lives together had begun sooner. He wished their time together would never end.

"That… was… amazing!" Entrapta declared between heavy sighs. "How did it feel for you?"

"The foreplay I found enjoyable. The device I am still growing accustomed to." Hordak gave honest feedback. He added a kiss to her cheek for emphasis. "Seeing you beneath me was the greatest treasure of all."

Entrapta's blush overtook her entire face. "Did you turn the sensors on in the penis?"

"I did not."

"Do you want to try it tonight? Just to make sure they work?"

Hordak had no doubt in their invention's functionality, but he was more than willing to engage in a second round with Entrapta. He found the switch on the underside of the device's base, then flipped it on.

The first thing Hordak felt down there was stickiness. Entrapta's juices from before covered the device. Now exposed to the heated air between their bodies, the sensation was the slightest bit uncomfortable. Hordak went to wipe the fluids away-

-but Entrapta beat him to it. Her bare hands wrapped around the shaft of his penis, stroking up and down and spreading her lubrication evenly across the device. Because they'd installed an extra sensitive sensor on the tip of the penis, Hordak inhaled sharply when her thumb flicked over it. Once again, the feeling was like nothing Hordak had ever known.

Entrapta kept up her massage of the device, grin growing ever wider as Hordak melted under her touch. His purple eyes glowed brighter. His moans turned to howls. Hordak didn't think his body was capable of producing an orgasm, so the pleasure he felt simply grew to ever increasing heights.

When the barrage of sensations became overwhelming, he pulled himself away. It took several breaths for him to regain the power of speech. "That… that is the most incredible invention you have ever made, Entrapta. You… you are a genius beyond compare."

"Yay! It works." Entrapta applauded their joint effort. "Don't forget you made it too, Hordak. This discovery wouldn't have been possible without you.

"You're my lab partner. I don't want to run these experiments with anyone else."

Hordak's purple eyes changed hue to joyful yellow at Entrapta's confession. His heart beat in double time, though not from exertion. Rather, from love.

He took her hand in his own, touch gentle and innocent. "I… love you, Entrapta. I would never have thought to try these things with anyone else. You gave me a life worth living, and I will always be in your debt for that."

Hordak smiled, his grin containing a hint of mischief. "Now that we've run our first two tests… are we ready to attempt a joint trial? Penetration with the sensors on?"

Entrapta returned his grin with eyes truly manic for science. "I was hoping you'd be ready for it tonight!"

And so their experiments continued well into the morning. The pair tested out a variety of activities and positions, doing a poor job of recording data all the while.

Lucky for them, Imp had made his own recording. "Do not disturb" did not exclude him from watching, after all.


A/N's: Thank you all for your patience. We have finally reached the end! I hope the smut lived up to your expectations. Smut is not my forte, and these two have some pretty unique circumstances between the two of them.

Obviously not every plot thread from this story gets resolved. Hordak may still have some lingering jealousy for his brothers, and the other princesses still don't fully accept their relationship. But what's more important is that the two are being honest with each other about their feelings and are spending quality time boinking together. I'm sure they will also make a great many discoveries in Horde Prime's memory core.

I won't promise to ever return to this ship or this fandom, but I haven't closed the door on it either. SPOP still has a special place in my heart. Thank you to everyone who supported this fic and waited YEARS for me to finish it. Hurrah!