Alex has a bad habit of walking in on Kara and Lena making out .
The first time it happens, Kara hasn't told her sister that she finally confessed her feelings for Lena and that the CEO said she felt the same. Alex and Maggie have plans that day to meet Lena and Kara for lunch.
They arrive about ten minutes early, the line at the local bagel place having been quite short. Alex doesn't bother knocking as Lena has told her to not bother with it before. When she opens the door, however, she is shocked by what she sees. Kara has Lena pinned on the couch. The pair are kissing passionately, but break apart and stand up the moment they notice that they are no longer alone.
"Uh, hi guys. So Lena and I are dating now," Kara states.
"We can tell, Little Danvers," Maggie laughs, "Lena, you have a hickey on your neck."
This causes Lena to blush furiously. The raven haired woman hides her face in Kara's neck, earning more laughter from Maggie while Alex simply avoids eye contact with Lena and Kara.
The second time it happens is about a month later. Alex is making her way through the DEO, planning to head home to Maggie, when she finds Lena and Kara once again making out. Lena has the blonde superhero pressed up against the wall. Kara's hand has snaked its way up Lena's dress shirt.
"Seriously! Not again! At least find a room with a lock on it!" Alex scolds.
Lena and Kara pull apart. Both are blushing bright red. Alex just sighs. She really hates walking in on Kara. Kara is her baby sister, after all. Seeing her kissing someone is just gross.
"Sorry, Alex," Kara flinches. She hates being walked in on as much as her sister does.
"It's fine. Next time, locked door. Now, I'm going home to Maggie. Goodnight," Alex replies.
"Goodnight, Alex," Lena states, still bright red.
"Night, sis," Kara adds.
Alex drives home on her motorcycle. She opens the door to her apartment to find Maggie on the couch. Alex kicks off her combat boots before joining the detective on the couch. She hides her face in Maggie's chest and groans.
"Hey love. You okay?" Maggie questions.
"I walked in on Lena and Kara again," Alex sighs.
Maggie just chuckles at this. This causes Alex to pout, but Maggie quickly kisses the pout away. Content now, Alex snuggles into Maggie's chest once more, and a peaceful bliss drifts over the pair. Alex won't ever be able to remove the image of her baby sister and Lena making out from her mind though, but she is glad Kara is happy, even though she is scarred for life now.