The first time Kara says it comes as a surprise.
Having sent Kara a boatload of flowers as an expression of gratitude, Lena wasn't familiar with the idea of friends, of someone who is there for you through the good and the bad. Someone who stands up for you without wanting anything in return.
So when Kara responds to Lena's thanks with a mere "well, that's what friends are for", you can understand why she would be surprised. After all, she's never had friends or family like Kara before.
Lena's never had someone who believes in her despite what everyone else thinks. Because of the Luthor name, constant dismissals were textbook for Lena. Most people wouldn't give her a second glance after finding out her last name and thinking of the horror that accompanies it, but Kara's different.
Somehow, Kara sees past the Luthor name. She sees past the prejudice and ignorance associated with it: she simply sees Lena.
Not Lena Luthor, CEO of L-Corp, or Lena Luthor, brother of Lex Luthor, or Lena Luthor, daughter of the woman in charge of Cadmus.
Kara sees Lena.
And for that, Lena couldn't be more grateful.
The second time, Lena is the one who says it.
It's almost teasing, a near quote of what Kara had said before.
Before she arrived, Lena's plans for the day had consisted of kombucha and spending time with Kara. Now, she is propelled back into reality with the latest news about Cadmus, which in turn means the latest news about her mother.
When Lena suggests to Kara to post her findings online, she truly believes it is the right thing to do. With Snapper Carr not willing to publish the news, it is essential to get the information out there, no matter the form, in order to warn the aliens about the kidnappings. Then, Kara asks Lena for a favor, and Lena knows she cannot deny her request. After all, they are friends now.
In fact, when Lena offers to look for the potential trail of breadcrumbs Lillian left behind, the words "what are friends for?" slip out of her mouth.
Because what are friends for besides looking into your bigoted mother's past to try to stop her alien-murdering organization?
The third time is frustrating.
Lena's having dinner with Jack when Kara comes in with [redacted], and Lena knows it's not a coincidence. Before, Lena had wanted Kara to talk her out of it, but she is enjoying Jack's company more than she thought she would. Kara's entrance is unwelcome, to say the least.
As Kara sits down, Lena explains that her rescue is not necessary, and Kara responds with the all too familiar phrase. That's what friends are for, apparently.
Lena is simultaneously amused and annoyed.
Kara questions Jack about Biomax, and Lena sees her opening to find out how he figured it out. They had spent countless nights trying to work out the science behind it, but they were never quite able to crack the code; Lena is dying to find out what the secret is. As he speaks, Lena finds herself remembering all the reasons that she used to love him.
But, later, when it comes to choosing between Jack and Supergirl, Lena chooses Supergirl.
Because Supergirl saves people. Because Jack would just continue to suffer. Because that bitch, Beth, needs to be locked away. Because that is what friends are for.
The fourth time is expected.
Yet again, Supergirl had just saved Lena, and Morgan Edge was being taken to jail. After the madness, during which she had lost track of Kara but found Supergirl, Kara comes walking back towards Lena.
Lena tells Kara that the reason she's not a killer is because of her friends, and there's never been anything truer. Without Kara and her unwavering loyalty, Lena would have made a terrible mistake. She would have teamed up with Lillian and killed Edge, or she would have done it herself some other way.
But friends, like Kara and Sam, they help her realize that she is above that. Lena is smart; she can plot and scheme to take cruel people down without resorting to murder.
They stick with her, no matter what. They stick with her through light times and dark times. Despite any crazy plan Lena comes up with, she knows that Kara will always support her and help find a way to make it happen. And Lena will always do the same for Kara.
After all, that's what friends are for.
Author's Note: This is my first Supercorp fic, so bare with me. Scenes included are from 2x12, 2x15, 2x18, and 3x12. Thanks for reading.
