Kara thought her cousin was lucky. All he'd had to worry about was his girlfriend finding out his secret identity, and that was really on him for dating a reporter in the first place. She had to worry about keeping it straight who she was dating in her secret identity and how she was confidently single in her other identity.

She slipped up occasionally.

She was going to see Lena Luthor about one of her scientists who'd gone rogue and started robbing banks—scientists, ugh, she hated to stereotype, but you never saw bricklayers turn to the Dark Side that much—and she kinda… forgot. That Lena Luthor was dating Kara Danvers, not Supergirl. So, seeing the window of Lena's office was open, she thought she'd just fly in and surprise Lena. Cutesy. Romantic. Adorable.

She was not expecting Lena to be bent over her desk, scrawling with furious concentration on notebook paper, everything about her rigid posture and focused gaze so intense that Supergirl just had to rethink interrupting her. And, abruptly, she realized that Supergirl and Lena Luthor were platonic friends, and Lena might take being goosed by her platonic friend the wrong way. Or she might like it and start coming onto Supergirl, and maybe cheat on Kara with Kara. That would be a pretty embarrassing way to get her heart broken.

At least she didn't have to come up with something to say, though. Lena noticed her standing there and hurriedly snatched the paper away, down into her lap. Kara stood there, a bit stunned. And now, suspicious. As CEO of L-Corp, Lena had immense power. And she was a Luthor. There was a reason Kara hadn't told Clark she was dating her.

But if Lena was bad, it concerned all of them. Clark had a right to know to be suspicious of her, especially if she was planning something. No matter what Kara's feelings were. She crossed her arms, a little defensively, and tried to ignore the tension that filled up the room.

"Supergirl." Lena tried to put a brave face on it. "This certainly is a pleasant surprise. And you've certainly found a way to decrease my secretary's workload—sneaking in like this…"

"Do you not want to see me?" Kara asked, struggling to keep the hurt out of her voice. Supergirl wouldn't care. Lena Luthor was nothing to Supergirl.

"You just surprised me, that's all. I certainly wouldn't come into your Fortress of Solitude without knocking…" She opened a desk drawer to slip the paper into—

"What were you writing?" Kara asked.

Lena looked up at her, intensely defensive. "It's private."

"I'd rather you tell me than I find out for myself," Kara pressed.

Lena set her chin and looked at Kara. "Back to thinking I'm some kind of criminal? Because Lex Luthor is my brother?"

"You have a lot of power. It demands scrutiny. And how can you be shocked at me being suspicious when you're acting so suspiciously?"

Lena ground her teeth together a moment. "Alright. If you must know. It's a private correspondence to my girlfriend, Kara Danvers."

Kara almost rocked back on her heels. "Oh."

"It's quite intimate. I don't care to share it with someone outside our relationship." Her eyes gleamed as they met Kara's. "Unless you're intending to participate in it."

Kara's relief got into a fierce arm-wrestling match with her embarrassment. "Participate in—oh, no, no, I'm not—"

"Gay?"

"Singl—looking for someone. I'm dating Lady Justice." Kara shook her head. "Or, Mr. Justice. I'm focusing on my work."

"Wise choice," Lena said, enjoying Kara's abrupt discomfort. "You sure you wouldn't like to look it over? Give me a little constructive criticism?"

"No, I'm sure it's fine. And that Ms. Danvers will love it."

"Thank you. And I assume you're here about that troublesome ex-employee of mine, Jacob Kahn?"

"Yes!" Kara breathed out, relieved she was off the hook.

"I've had my secretary prepare a dossier on him." Lena reached for the intercom button, but paused. "Of course, if you'd talked to her in the first place, she had instructions to just give it to you. It's what I pay her for."

"I bet she's very good at her job," Kara said weakly.

Lena held down the button. "Ms. Kowalski, please bring in the Supergirl file. The Girl of Steel has decided to forego the usual formalities."

Kara gulped, took the file delivered to her as politely as she could, and flew away at top speed.

It really wasn't fair that she could be dating someone and still get flustered by them.

"So, Supergirl said you were writing me a letter."

It was a cozy little dinner in the penthouse apartment of the National City Hilton, where Lena was staying as she continued sorting out a proper apartment. She was playing hardball with an Estate Row apartment, waiting for one of the rich people there to break and move away from the frequent metahumans attacks. Until then, she stayed in this slightly prepackaged state, with its sheen just a little off from her overall mien.

Kara had brought Chinese takeout, fulfilling her promise to take Lena on a tour of the city's delivery restaurants options, and things were intimately romantic enough to send Kara's princess fantasies into overdrive. She couldn't resist asking about her love letter any longer.

"She did?" Lena asked, surprised, and Kara actually stopped herself from taking another potsticker to answer.

"Mmhm. It was, you know, CatCo business, we were talking for an article, and she was all 'I hear Lena Luthor is writing you a love letter.'" Kara nonchalantly brushed a lock of hair behind her ear. "So fleek." She didn't know what that word meant, but humans seemed to like it a lot.

Lena's eyebrows raised. "I had no idea Supergirl was so starved for gossip that my… creative writing is worth commenting on!"

"Hey." Kara picked up the wine bottle and filled Lena's glass again. "It's sweet. It's way more sweet than just buying me something, because you can afford anything, but taking time out of your busy day to write me a love letter is really caring and sweet and—"

"It's not a love letter!" Lena snapped.

Kara pulled back the wine bottle so fast she accidentally sloshed some of its pouring contents onto the tablecloth before righting it. Lena sighed, crimsoning from the tone she'd used, and snatched up her wineglass to take a heady sip.

Kara put the cork back in the bottle before she proceeded. "Well, if it's not a love letter, what is it?"

Lena ground her teeth. No one but a Kryptonian could've heard them crushing together.

"Lena, you know you can tell me anything," Kara persisted, feeling vaguely sick with the renewed possibility that this was something bad, something kept hidden from Supergirl, but because of her lies she had a front row seat to its ugliness spilling out raw. She couldn't bear the thought of Lena, totally in love with her, totally trusting her, revealing some plan to destroy Supergirl…

Lena looked away. "You think it's some evil scheme too, don't you? Just like brother dearest would write…"

"I think that whatever it is, you believe it's right and for the best. That you wouldn't do it unless—"

"It's not a scheme." Lena didn't snap, but only because her voice was tightly controlled, wire-taut. "Not a plot, not anything like that…"

"So what is it?" Kara insisted. "Just tell me, I'll understand—"

"You weren't supposed to find out like this, Supergirl wasn't supposed to barge into our lives and tell you. I was going to let you know in my own time, in my own way—"

"Let me know what?" Kara demanded, so tense she wondered if her eyes were glowing red.

Lena let out a deep, shuddering breath and turned to face Kara once more. "It's… things I'd like you to say to me."

Kara was mystified. "You mean like a poem?"

"Not like a poem. More like… pillow talk. Things you could say to me when we're intimate."

Kara managed to restrain a relieved laugh, but she couldn't quite keep herself from smiling. "That's all? Lena, that's fine. Whatever it is, you know, I'm sure I'll be comfortable with it."

Lena shook her head, snatching up a napkin and wiping almost frantically at her hands. "Not intimate per se… it's like a scenario, Kara. You're one part of the scenario and I'm another. And I play one part and you play another part."

"Like you're a Viking and I'm another Viking?"

Lena got up, went to one of her suitcases lining the wall, picked it up, virtually slammed it on the bed, and opened it. "This is the L-Corp 591 Extrahuman Restraint Model. It's designed to actively suppress metahumans abilities and restrict humanoid lifeforms with vast morphological differences from human beings."

It looked like something a mental patient would wear while playing Lazer Tag. "Oh, okay," Kara said.

"I want you to put it on me and activate it so I can't move. And then you say those things to me while I'm tied up."

"Are the things about spanking you?" In all the scenarios Kara had imagined holding back her strength, that one had never come up. How hard would human Kara spank someone anyway?

"No, no spanking," Lena said, strained. "I'm just tied up. I'm tied up and I can't move and I can't get out. And you're holding me prisoner and you talk about how I can't get away and I'm yours forever and… stuff."

"Oh," Kara said.

Lena huffed, as if she were the one exasperated with Kara's eccentricities. "Look, I'm Lex Luthor's sister, you should've expected there would be more in the tank here than reverse cowgirl."

"No, no, I get it. It's just a fetish. I'm fine with fetishes."

As if completely wearied by her reveal, Lena slumped down onto the bed. "I keep imagining what people would say if they found out. 'Look, two Luthors in chains.' It's not that weird, is it?"

"No!" Kara protested. "Tamaranians like to carry each other around on their backs when they're courting. That's way weirder. This is just one particular aspect of the human mating ritual."

Lena nodded. "That's a very mature way to look at it, Kara."

Kara bit her lip, realizing it was also a somewhat alien way to look at it. Probably not Lena's favorite thing. "Yeah, I'm sure you would be fine with me if I had a fetish."

"You don't have a fetish?" Lena asked.

"No, I don't think so—"

"It's just you really like it when I pull your hair."

"It's the way you do it—"

"I thought it was a thing with you."

"You're very forceful. It's… interesting."

Lena smiled, relieved. "So you wanna try it out?"

"The, uh, 591 Extrahuman Restraint Model?"

"Yeah!" Lena nodded. She reached into her blouse pocket. "Here's the 'love letter.'"

Kara took it from her. "I am so glad you told me all this, however Supergirl was involved. Just because I'm a certain way in public doesn't mean I don't also own my sexuality. Yeah, bring on the fetishes, it's just part of my best girlfriend ever bonus round."

Lena bit her lip, charmed. "You're going for best girlfriend ever?"

"Mmmhmm."

"I kinda thought that could be me."

"Write me an actual love letter first, not Fifty Shades of Gray fanfic." Kara opened up the folded note. "Oh!"

"What?" Lena asked, leaning over.

"Nothing!" Kara shrunk away from her, hiding the letter, before remembering Lena knew what was on it, having written it. "It's just I didn't expect it to be so… graphic. Not right off the bat."

"I don't like pussyfooting around."

"It's fine," Kara assured. "Just get it all out in the open, right out there…" She read more. "Oh wow, that's more graphic. That's… wait, why wouldn't you be able to see this?"

"Because I'm blindfolded."

"And no one can hear you scream because—"

"Gagged," Lena pronounced with relish.

"I see." Kara coughed a little. "And what if you're not really… d… 'dripping like the outside of a water bottle'?"

"Well, you've said the other things first, so I will be."

"And do I really have to… while I'm looking at you…?"

"No, I'll be blindfolded, it's just part of the fantasy." Lena glanced at her. "You can if you want to."

"Because you're supposed to smell me doing it—" Kara turned the letter over. "Oh, there are two sides."