A thing Alex learned very quickly about her new sister is: the more Kara talks about something, the more she isn't actually saying anything really important about it.
It was little things, when they were younger. The fifteen minute architectural history lecture that ultimately did nothing to hide the fact that Kara had accidentally broken every window in her room trying to get closer to the sunlight. The week she spent muttering about math is definitely fake, and imaginary, and made up, and do I have to be in this class anyway before Eliza and Jeremiah realised that Kara, bored with concepts she learned years ago and too afraid to show how far ahead she was, had been turning in blank homework and test papers.
So when James Olsen's ex-fiance moves to National City and Kara stops blushing at every mention of his name and starts saying things like Lucy was wearing the best perfume today and I can speed-read anything I want but this contract Lucy wrote was so clever that I didn't even want to, Alex knows exactly what's going on. Knows, probably, before Kara does, because she's spent so long picking apart romance trying to make herself feel any affinity for it that she's grown good at recognising the signs.
Kara loves most people in her life without reservation or distinction as if her love alone can keep them safe forever.
Kara also so definitely has a crush on Lucy Lane.
Which means that gentle mocking of the sort that eventually leads to Kara asking Lucy out is practically her sisterly duty.
"So," Kara says two weeks after Lucy joins CatCo, on one of the rare mornings they've actually managed to meet up for breakfast without getting interrupted by an alien invasion or (worse) one of Cat's demands, "We're going to Sephora tomorrow."
Alex doesn't even have to think about that one. "Nope."
"Why not?" Kara demands. "I've seen my training schedule. There's plenty of time. And Lucy was wearing this really great lipstick, which made me start to think about, you know, Cat wants Supergirl to start doing more public appearances, and I should start thinking about my image for that, and also, Kara Danvers should be allowed to do something interesting with her makeup if she can't with her hair and --"
Oh. "Kara," Alex says, holding up a hand and resisting the urge to close her eyes against her non-existent table manners. "Kara. Come on. Have you considered that just complimenting a girl on her lipstick and asking where she got it might be the more effective pick-up line?"
"Pick-up line?" Kara's voice rises in an alarm completely at odds with the blush staining her cheeks. "I'm not -- who said -- she just looked so -- and I thought --"
Alex rolls her eyes affectionately. "Okay, miss she's gorgeous, she's smart, she smells nice, I'd want to date her, no one's trying to get a date with Lucy," she says. "You're still going to Sephora by yourself."
Kara sighs. "You know I could bench-press you with one finger, right?"
"Uh-huh," Alex agrees. The threat might carry more weight if it wasn't garbled around the half a cinnamon bun in Kara's mouth.
"I mean it," Kara insists, slightly more intelligibly. "Next practise session. You're going down."
Alex smirks. "Didn't we just establish that you'd rather be going down on Lucy?"
Kara squeaks. Alex sticks her tongue out and definitely does not get so distracted laughing at her that she walks into the doorframe on her way out.
So maybe some version of that conversation happens every other day for two weeks over breakfast. It's not Alex's fault. If her baby sister could just be less of a, well, baby about asking Lucy out...
Alex is almost tempted to do it for her, but that just leads to a whole lot of bad romcom-inspired worst-case scenarios where she ends up on a date with Lucy and, wow, no.
But speaking of bad romcoms, accidentally tripping over something during game night and accidentally shoving Kara into Lucy's lap is getting more and more tempting by the hour.
Somehow this gets worse after Lucy joins the DEO full-time and learns Kara's true identity.
"Kar, come on, you have no excuse now. N-o-n-e none." She swipes a curly fry from Kara's plate to emphasise the point and doesn't even complain when Kara uses a split-second of superspeed to get it back. "See, you have superspeed. What girl can resist that?"
Kara looks contemplative, and Alex suddenly suspects she's about to get a list of all of Kara's past failed romantic endeavours. "Okay, forget that. Lucy Lane is definitely not gonna resist that. I've seen how she looks at you in your whole Supergirl getup."
"She looks at me?" Kara's entire self brightens momentarily, and then she frowns. "How does she look at me?"
Alex will not bang her head against the back of the couch. Why must all the lovable aliens she's surrounded with be so utterly clueless? "Like she wants to do all sorts of things to you that I never in a million years want to think about anyone doing to my little sister."
Kara's eyes widen. "I wouldn't m -- you know what, I'm not gonna finish that sentence because you might kill me, but . . . okay. Tomorrow. Tomorrow I ask Lucy out."
Alex's affection for her sister in that moment is matched only by her desire that she sound half so serious about her hand-to-hand training sessions.
Lucy shows up at the DEO the next day on a motorcycle. Alex is grateful that Kryptonian powers do not extend to the sort of super-flexibility that would allow Kara's jaw to actually drop to the floor.
And maybe Alex is staring a bit too, because Lucy Lane in leather and denim and fingerless motorcycle gloves? She's getting a somewhat better idea why Kara's spent so long staring and so little time talking.
But she nudges her sister forward across the sand anyway, because if Kara doesn't do this now she'll end up doing it in front of the control room, and no one wants that.
"Hey," Lucy greets them as she drags her helmet off and tries to maneuver it around her one armed hugs. "Morning Alex, Kara."
"Hey," Kara says, and she's hardly blushing at all. Alex is so proud.
"Thank you for not calling it good," Alex manages around a faceful of Lucy's windswept hair.
Lucy laughs, trying to blow her hair out of her own face. "When is it ever?" She fishes for her hairclip, losing the battle against the strands still clinging to her mouth. "I hate it when my hair sticks to my lipgloss. It's so not superhero."
Alex snorts at the reference, but Kara steps even closer to Lucy, brushing the hair from her lips with impossible tenderness. "No," she says softly. "It is incredibly superhero on you."
And then she's tilting Lucy's face up, and leaning down, and pressing their lips together, and that's --
-- that's Alex's cue to leave, and she does just that, grinning the whole way to her office.
She really is the world's greatest sister.
"Danvers," Lucy hisses in her ear twenty minutes later. "You're a terrible older sister!"
"What did I do?" She asks. I was the one who encouraged her to go after you, is on the tip of her tongue, but even she knows that's not something you say to your sister's . . . girlfriend? Does one kiss make you girlfriends?
Lucy crosses her arms. "Kara didn't understand the Sanctuary reference."
Oh. "Hey, I started her off with Stargate! It's not my fault there's thirteen seasons of that."
Lucy, who is the sort of completionist traitor who counts the last two seasons of Atlantis and both seasons of Universe as things that exist, does not look impressed. "We're fixing that. You and I. Starting tomorrow."
Alex raises her eyebrows in faux innocence. "Oh? Why not tonight?"
"Tonight," Lucy grins smugly. "Tonight I take Kara out to dinner."