It was dark by the time Kara felt that she could go home. She had been flying around the city, saving cats (actual cats) from trees, stopping one small convenience store hold up and flying one man to the hospital because the ambulance didn't come fast enough. Really, the city didn't need her today, but she needed them, so she continued. She needed people to say "supergirl!" with that small breathy sigh that indicated she had helped, that she was important.

The fight with that dumb AI had left her exhausted, but none of this work, with people smiling her, was making her feel better. She gritted her teeth, and changed her direction.

She wasn't going to go back to her own apartment tonight. It was too small, too tight, too lonely . She wanted Alex.

Alex always left the window into the spare bedroom unlatched. She lived on the 12th floor, so it only took one quick glance around for Kara to secure the area and slowly climb in. She glanced through the bedroom wall and caught sight of Alex, sitting on the sofa. Kara frowned. Alex was unnaturally still, her posture stiff. Kara could feel the nervous tension roll off her in waves as she clambered in through Alex's window. She didn't look up from where she was sitting on the sofa, bent over, her head in her hands. Kara cocked her head at her, and then started shedding her cloak.

"Alex?" she called, taking off her top. Alex didn't respond. Kara paused and, picking up one of Alex's shirts out of the laundry basket, toed out of her boots and padded over to Alex. "Alex?" She asked again, quieter this time as she sank to her knees and carefully placed a hand on Alex's knee. "Are you okay?"

"I'm fine," Alex muttered, inhaling deeply and trying to sit up. Kara fell back on her haunches and tilted her head slightly to the right. Alex smiled at her weakly and covered Kara's hand with her own. "I'm just tired," she said, grim smile on her face. Kara didn't return the smile.

"It doesn't take a kryptonian to tell you're lying, you know?" Kara murmured gently, reaching up to cup Alex's cheek gently and brush one of the tears away with her thumb. Alex leaned into the touch and smiled sadly.

"No really," she began but Kara shook her head.

"Don't tell me it's nothing," Kara murmured. "You can't always be the big sister, Alex." Alex sighed and looked at the back of the room, her eyes unfocusing.

"I killed a man, Kara," she whispered. Kara stayed motionless, trying to digest the words.

"What?" She asked quietly, her voice gentle and calm while her thoughts were racing at 100 miles an hour.

"That man controlling Red Tornado? I had to kill him." Kara didn't let any of her microexpressions give her away, but she felt relieved. Him . He was bad. He deserved it. Kara focused on Alex again. She didn't look relieved. She glanced at Kara, and then looked past her again as her voice dropped down to a whisper. "I had to look him in the eye and shoot him in the chest."

"But he was bad, Alex," Kara murmured.

"Doesn't matter," Alex whispered bitterly. "Now he's dead." Kara could her the edge of self-loathing, and she carefully started rubbing Alex's knee as she made an empathetic noise.

"Oh Alex," she whispered after a couple of second of silence, bringing Alex back to the present. Alex looked Kara in the eye again, but this time she held her gaze.

"I did it for you, Kara," she whispered. Kara wasn't sure whether there was any accusation in her voice, so she just scooted forward and responded in her warmest, most comforting tone.

"I know, Alex." Alex grimaced and unfocused her eyes again. They were silent for a minute, and then Alex's gaze snapped back to Kara.

"I did it to save you," Alex repeated, holding up a hand and carefully caressing Kara's cheek. Kara stilled at the touch, careful not to push Alex any further. Alex smiled sadly and then shook her head, dropping her hand again. "I did it for you and it didn't even help , Kara."

"It helped, Alex!" Kara began, hurriedly trying to make it right again. She grabbed Alex's hand. "He had me in a death-"

"It didn't stop the machine though, Kara," Alex whispered. Kara bit her lip. It didn't. Alex had murdered a man, and instead of stopping, the machine had become sentient. She took a deep breath, and then deflated. She didn't know what to say.

"I'm sorry," she whispered.

"I've never killed another human being ever , Kara," Alex hissed, shaking off Kara's hand, "and all you can say is 'sorry'?" Kara sank to her knees, head bowed as despair welled up in her chest. Alex was right. This was her fault.

"I've shot aliens, I've put bad people into prison, and I have watched men die in the field, but I have never in my career as a field agent taken someone's life." Kara bit her lip. She felt helpless; how could she get Alex out of this?

"Oh, Alex," she repeated. Alex stiffened and glared at Kara.

"Don't 'oh Alex' me, as if this is something small." She snapped, pushing away Kara's hand on her knee. "It's not , Kara. I'm a murderer now."

"Alex –" Kara tried, but Alex was too upset now.

"Kara!" Alex shot up, and Kara fell back onto her ass. She watched Alex pace, her tears forgotten, a newfound anger in her system. She bit her lip, considering for a second, before she slowly got up and approached Alex from behind.

"You killed someone for me ," Kara murmured, placing a hand on Alex's shoulder warmly. Alex whirled around and stared at Kara with wild eyes, about to say something, but Kara held up a hand. "You saved me, Alex," she whispered, cupping Alex's face. " You . Alone. You're always saving me." Kara stepped closer, so she was in Alex's person space, and stared into her eyes. She wished she could let Alex know about every time that Kara ever loved her, she wished she could show her all the different times she had saved her. Language seemed so inadequate . Kara tried to formulate her feelings into words anyway. Her hand drops from Alex's face and grabs her hand so she can squeeze it, a familiar sign of reassurance. "I couldn't do any of this without you," she whispered, her voice almost hoarse. Kara gazed into Alex's dark eyes, and felt the space around them begin to tighten. Alex reached a hand out and carefully traced Kara's cheek again with her thumb. Kara leaned into the touch and kissed the palm of Alex's hand lightly. Alex stepped into her space and kissed her. It was a hungry kiss; Alex's left hand slipped from Kara's cheek to the nape of her neck, tugging her closer, tilting her head back. Kara knew this edge well; Alex needed assurance, a reminder that Kara was hers , a reminder that she had done the right thing. Kara immediately returned the kiss with warm and pliant lips as she lifted her hands to Alex's shoulder.

Alex was so familiar; Kara knew every part of her. Her eyes fluttered closed as her right hand settled on Alex's hip and she she brushed a thumb over Alex's skin. She opened her mouth to Alex, and Alex licked into her; Kara whimpered into the kiss. Alex was exploiting her every weakness, and she just submitted to her.

"Kara, tell me you need me," Alex whispered, her voice sharp with desperation. Kara stared into Alex's eyes, her smile small and comforting.

"I need you" she panted, running a hand through Alex's hair. Alex pushed Kara against the wall, and Kara made herself soft, giving into to all the spots of pressure where Alex pushed her. Alex pushed herself up onto her tiptoes to be taller than Kara, and Kara slid down the wall slightly to let Alex stand above her. Alex kissed her again, and this time she scrapped teeth over Kara's lips and Kara whimpered. Alex placed her left hand on Kara's cheek and slowly slid the hand down to Kara's neck, which she caressed gently with her thumb. Alex's hand on Kara's neck, which didn't do anything, so clearly signalled power and control made Kara weak in the knees. Alex's need to exert control was so palpable between them, and Kara was too aware of how hot it was. It was almost embarrassing.

Alex's kiss was sharp, and her teeth tugged on Kara's lips as her right hand slid up under Kara's skirt. Kara had forgotten she was still partially wearing her Supergirl uniform, and she gasped as Alex ran her nails over the tights on her thigh. "I'm all yours," Kara repeated, her breath embarrassingly out of sync with Alex's far slower, more steady breathing.

Alex's hand dug into Kara thigh and she stopped kissing Kara for a second. "Bed," she ordered quietly, and although it took Kara a second to disentangle herself, she immediately followed the order. "Take that off," Alex added, indicating the shirt. Kara pulled it over her head and then settled down on Alex's bed facing her. Alex stepped out of her own clothes hurriedly and then settled down on Kara's lap in only her underwear. Alex's knees on either side of Kara's hip guaranteed that she was taller than Kara again, and she slid her arms around Kara's neck as she began kissing her hungrily again.

Kara gave a small moan. It reverberated through Alex, echoing through her skin, and she wanted more. Alex bit Kara's lip. Kara arched into the touch. Kara was so familiar, so predictable; Alex knew every spot of her. Alex bit down on Kara's neck and sucked; no hickey bloomed on Kara's skin, but Kara did give out a small cry as her hand dug into Alex's thighs. Alex felt the tiny electric shocks of pleasure that the

"I hate that you don't bruise, sometimes," Alex whispered. That sentence shouldn't have thrilled Kara, but she felt her whole body respond to Alex's frustration and she made a small pleading sound. Alex kissed her again, lightly blowing on the small spot of saliva so that a small jolt of cold ran through Kara's skin. Kara groaned again, and ran a hand through Alex's hair, pulling her up. Alex kissed her again and Kara found herself making a small pleading sound at the back of her throat, trying definitely to push up her hips. Alex lightly pushed at Kara's shoulders, and she automatically fell back onto the mattress. Alex leaned over her and kissed her once, lightly, and then trailed kisses down her torso, through the valley of still clothed breasts. Kara writhed under her. Alex smirked.

"Alex," Kara panted. " Alex ." Alex ignored her, carefully kissing the bottom of Kara's bra. Kara's breasts were so sensitive; Alex loved torturing Kara like this. She loved watching Kara writhe and claw against the bedsheets, whispering her name like a prayer. She nipped the underside of Kara's bra. Kara groaned and her hips buckled up, searching for friction against Alex's bare leg. But Kara was still wearing her Supergirl tights and skirt, and Alex gasped, surprised at the effect the rough fabric of the tights had on her. Kara tried her best to smirked at her, but her hair was tousled and her pupils turned the smirk into a leer. Alex kissed her again with a laugh.

"I think we need to take those off," she murmured.

"Please," Kara begged, lifting her hips. Alex slowly pulled down the tights, leaving small delicate kisses on the expanses of skin exposed. Kara whined.

"Alex," she whispered, breathily. Alex grinned.

"Pass me the pillow," she instructed. Kara immediately complied, and Alex slipped the pillow under Kara's ass. Kara shifted.

"Aren't you going to...oh…." She trailed off as it became obvious that Alex was not going to remove her Supergirl skirt, and instead began trailing kisses up Kara's thigh. As Alex's brown hair disappeared under the bright red skirt, Kara grabbed the bed sheet and hissed. Alex kissed Kara's clit over the surface of her underwear, all too aware that her warm breath, as well as the pressure on hypersensitive flesh, was too much for Kara. She didn't let herself touch Alex though, for fear of hurting her fragile calcium bones, so instead she gripped the fabric on the bed spread and whined.

Alex was a terrible tease; she licked Kara's clit over the fabric of her underwear and then carefully, ever so carefully , removed the underwear with her teeth. Kara groaned, and pushed her hips up, demanding release from the pressure building in the back of her spine. She felt like her whole body was quivering, shimmering with power, and if Alex would just touch her -

Oh.

Alex heard the sheets of the bed rip as she ran her tongue through Kara's labia. Kara tasted sharp and metallic, and Alex wanted to consume every part of her. Her own arrousal was distracting, but Alex wanted to focus on Kara, prolonging her torture, listening to the many ways Kara said her name. She repeated it like a litany as Alex's hand slipped into Kara, and Alex felt like she was going to get high on Kara's breathy repetitions of her name. As her hand set a slow, lingering pace, Alex alternatively sucked and pushed back at Kara's clit with the flat of her tongue, pushing Kara's breathing higher. Alex hummed into Kara, and she felt the beginnings of her orgasm ripple through her.

With a long lick of the flat of her tongue against Kara, Alex pushed her over the edge; Kara arched against Alex, and then levitated above the bed as her orgasm surged through her. Alex felt her own body clench; somehow, without even touching herself, this made her come. She pulled at Kara lightly, and Kara fell back on the bed. "Kara," Alex whispered in part wonder, part desperation, her voice breaking. Kara's eyes flew open. She leaned ran forward and runs her thumb across Alex's lips.

"Let me touch you," Kara murmured. Alex noded weakly. Kara smiled and traced small circles into Alex's skin, kissing Alex's exposed abs, while her hand slipped into Alex's pants. Alex was so wet, and Kara shifted against her, slipping two fingers into Alex and then using her own hips to carefully set a rhythm. Kara smirked when Alex didn't last long, her hand grabbing Kara's ass to encourage her to speed up the pace. Kara kissed Alex's collarbones lovingly and chuckled.

"I love you, Alex," she whispered, and Alex gasped, her body overcome with her second orgasm. Kara chuckled and buried her face in the crook of Alex's shoulder as she relaxed on top of her.

"I love you too," Alex whispered, kissing the top of Kara's head.

Kara stroked Alex's face softly, carefully tracing her cheekbones. "I love you," she whispered, leaning forward to give Alex the softest of kisses. Alex looked at her, and Kara smiled sadly. She held up one of Alex's hands. "I would love you even if you had the blood of 20 men on your hands, Alex." Alex snorted.

"Only men?" She asked, raising an eyebrow. Kara rolled her eyes.

"Alex," she warned. Alex sighed and pulled at the blanket so it covered them partially before she turned to look at Kara again.

"I'm not worried about your love, Kara," she admitted. Kara smiled for a moment, before she titled her head questioningly.

"What are you worried about?" She asked. Alex bit her lip and rolled onto her back, so she was staring at the ceiling.

"I suppose I'm most scared of becoming someone I am not," she told the white plaster. Kara shifted closer to her and continued looking at her. Alex didn't return the gaze/

"What do you mean?" Kara asked quietly. Alex bit her lip. While she was lying here in bed, pleasant exhaustion thrumming through her, the idea of killing for Kara didn't feel so terrible anymore. That was something that the part of her that was a DEO agent had to do. That blood on her hands wasn't on her hands… Alex sighed and turned to look at Kara agin.

"These last 6 months at the DEO have been...so stressful? I'm worried I'm losing myself." Kara considered Alex, and then flopped down on the bed next to her, so they were lying shoulder to shoulder, both of them staring at the ceiling. Kara threaded her hand through Alex's and looked at her foster sister steadily.

"Do you wanna know what I think you are?" Kara asked, her earnest blue eyes shining with sincerity. Alex raised an eyebrow and rolled onto her side so she could look at Kara better.

"What do you think, Kara?" She asked. Kara grinned and tucked a strand of Alex's hair behind her ear lovingly before she brought up their entwined hands and gently kissed Alex's hand.

"I think you're kind," she murmured, kissing Alex's forehead. "Compassionate." She kissed her right eyelid. "A little bit bossy." She kissed her left eyelid. "Amazingly smart." She kissed her nose. "And the most sexy person in the world," she ended, kissing Alex on the mouth. Alex laughed into the kiss, and it was almost like Kara could taste the bubbles. She leaned into Alex and made their foreheads touch.

"But really," she whispered quietly, "we should make sure we have more time to ourselves."

"You can't -"

"I'm Supergirl , for god's sake, Alex. And you're Hank's protogee. If we tell him we need a day or two off, he'll give us a day or two off."

"Kara, do you really think you could take an entire day off?"

"Well, if I had a really good distraction, I might be able to."

"You put far too much faith in me." Kara raised an eyebrow, combing a hand through Alex's hair.

"Or you're just that good," she murmured.