But Emily’s relationship with Naomi is set against the backdrop of the larger story of Emily’s quest for independence from her sister. Coming out becomes a catalyst for Emily to stand up to Katie, as Katie’s refusal to accept Emily’s sexuality, and her attempts to ruin Emily’s relationship with Naomi, finally spur Emily to make a long-overdue break from her sister.
Emily comes out to her family in this episode, telling them bluntly over dinner, "I’ve been making love to a girl … Her name’s Naomi, she’s rather beautiful, so I was nailing her." Katie tries to stop her, but her parents don’t believe her, anyway — Dad pretends it’s a joke, Mom pretends not to believe it.
Katie follows Emily upstairs to their room and tells her, "you’re not gay, you’re just stupid." She accuses Emily of making up this affair with Naomi because "I get more boys than you, I look better in clothes than you, and I’m more popular than you."
But Emily fights back this time, pointing out how dysfunctional Katie’s relationships are, and — referring to Katie’s physical altercation with another girl over a boy in the last episode — says harshly, "Nobody hits me over the head with a rock."
But when Katie turns without a word and climbs into bed after this fight, Emily tries again to win her sister’s approval, saying "I’m still Emily," as Katie ignores her and cries in bed.
Even Katie and Emily’s mother sees the uneven power structure, telling Naomi later in the episode, "[Emily's] the younger twin, and that means somehow she’s always in her sister’s shadow … Katie’s always in charge."
When Naomi goes to Emily’s house to apologize after their night together ended in Emily leaving upset at being "an experiment," Emily’s mother asks her inside for a chat that quickly turns ugly.
Mom: I want you to stop putting ideas into her head, OK? She’s not gay.
I’m not gay.
Right, so there’s nothing to worry about then, is there? Because they’re the apple of their dad’s eye, he loves them like fierce, you know? Just the way they are — normal, happy twins. And they’re more alike than you’ll ever know.
Naomi: you sure of that?
Mom: I want you to disappear now, Naomi. Don’t screw her up, OK? Goodbye, Naomi.
Naomi leaves, and Emily never finds out about Naomi’s visit.
When Katie later learns that Emily had once slept with JJ, she calls Emily a "secretive little cow" and tries to assert her authority over Emily again.
Emily: Well, if I felt like having sex with him, I don’t have to ask you.
Katie: Yes you do.
Katie: You have to ask me! [Repeats these words in twin language]. (pause) Not gay, stupid!
Katie clearly senses that Emily is breaking away from her and is desperate to stop it, even reverting twice to using the secret twin language the girls haven’t used for years.
Finally, Katie decides to take matters into her own hands, and when Naomi calls Emily and begs her to meet for coffee, she finds Katie there waiting for her, instead of Emily.
Katie: Leave her alone, she’s mine.
Naomi: She can’t help what she is, Katie. Neither can I.
Katie: Yeah, seems like she could help it when she was f—ing JJ.
Katie: Apparently he’s quite keen actually, you know, after she saw to him good and proper.
Naomi [stunned]: It’s not true.
Katie: You hurt her, now she doesn’t want you. [gets up to leave]
Naomi: Why are you so horrible?
I love her more than you ever can. Now if you’ll excuse me, I have dresses to buy for the ball. You won’t be there, because if you are…" [glares menacingly before walking out]
She leaves Naomi wiping away tears.
At the house that night, Katie is trying to get Emily to go to the ball. She tells a despondent Emily, "[Naomi] doesn’t want to go with you, and I do," and reluctantly, Emily puts on the dress Katie gives her to wear.
But Naomi unexpectedly shows up at the ball — and makes it clear to Emily that she now knows about her and JJ, before walking into the dance alone.
As a crushed Emily heads for the parking lot, Katie pounces on Naomi inside, slamming her against the wall and telling her, "She’s my sister, you’re just a slut." (Ironic, coming from Katie, but nevermind.)