During the performance of Lean on Me, they are seen hugging and giving each other high-fives.
Rachel asks Brittany to be in the yearbook with her, but she refuses after saying she doesn't want to be in a picture that will get defaced. When Rachel tries to confirm that it won't, Brittany says it will because she'll be doing the defacing.
Brittany sings back up with Santana as one of the angels in Rachel's music video of Run Joey Run.
Brittany and Rachel are seen dancing with each other during the song One.
When Rachel comes into the choir room with her theatricality costume, Brittany says, "You look terrible, I look awesome."
Brittany tells Rachel that she is more talented than her.
Rachel tries to make a comeback at McKinley High by setting a fashion trend. She gives Brittany her allowance money to use one of her trademark accessories, her legwarmers, but Brittany messes it up by wearing the warmers on her arms. When Rachel sees her wearing them like that, she gets angry at her and tells her to wear them on her legs. After that, Rachel sees that the 'armwarmers' have become a new trend at McKinley, but that Brittany is getting the credit for it. Rachel, determined to succeed, decides that Brittany should go all out "sexy schoolgirl librarian chic." Once again, it becomes a trend and Brittany gets the credit and an interview with Teen Vogue. Rachel is left furious.
During the Tik Tok performance, Brittany tells Rachel that she is feeling sick. Rachel responds by encouraging her to "power through it." Unfortunately, Brittany throws up on Rachel at the end.
Brittany claims that Rachel's song My Headband is her favorite song ever.
After Santana shows her a voodoo doll that she made to resemble Rachel, Brittany convinces Santana not to be mad at her about losing Nationals because she feels that this year wasn't about winning.
Brittany campaigns against Rachel for senior class president, and tries to gain votes by stating that Rachel is still on MySpace.
Brittany is seen at the courthouse after Regionals as one of Rachel's bridesmaids.
In Prom-asaurus, Brittany first mistakes another girl for Rachel. Rachel, later, plans an anti-prom party which Brittany does not attend as she attends the prom she had planned herself because she is class president. In the end, Rachel and the others who were at anti-prom decides to go to the school's prom, Brittany was happy to see her and everyone else.
As Rachel and the other 7 seniors have graduated, the competition for the new star power, also known as "The New Rachel" is fierce. When Jacob interviews Brittany, Tina, Artie and Blaine as to who the new Rachel is, the four say "I am." Rachel watches the interview online saying she's happy that she's missed back there. Finally Brittany, Tina, Wade and Blaine compete for the role but, in the end, Brittany does not become the new Rachel, as she only achieved second place.
In the beginning of the episode, Sue brings Brittany to her office about her academic excellence while being on the Cheerios. On the other side of her test, she had drawn a picture of "the land where math doesn't exist." Brittany points out her picture of her, Santana, Sue, and Sue's baby, along with Rachel and Kurt in heaven. She also mentions in a voiceover that she's the new 'vice Rachel', referring to being placed second in the competitive run to be the "new Rachel" of the Glee Club in the previous episode.
Brittany mentions to Santana that Rachel has found a new love in New York, suggesting that Brittany pays attention to what Rachel has been doing in New York.
Sang Together (In a Group Number)
|Toxic||Britney/Brittany||Will, Santana, and Tina|
|Start Me Up/Livin' on a Prayer||Never Been Kissed||Santana, Tina, and Mercedes|
|Marry You||Furt||Quinn, Sam, Finn, Artie, Tina, and Mike|
|Loser Like Me||Original Song||Finn, Santana, and Mercedes|
|I Love New York/New York, New York||New York||Santana, Artie, Mercedes, and Finn|
|Light up the World||Santana, Artie, Tina, and Finn|
|We Got the Beat||The Purple Piano Project||Santana|
|Do They Know It's Christmas?||Extraordinary Merry Christmas||Santana, Artie, Mercedes, Finn, Tina, Puck, Kurt, and Blaine|
|Love Shack||Heart||Blaine, Kurt, Mercedes, and Sugar|
|Paradise by the Dashboard Light||Nationals||Finn, Mercedes, Kurt, Blaine, Santana, Mike, and Puck|
|The Scientist||The Break-Up||Finn, Santana, Kurt, Blaine, Will, and Emma|
|You're the One That I Want||Glease||Ryder, Marley, Finn, Santana, Kurt, and Blaine|
- Run Joey Run by David Geddes. (Bad Reputation)
- Tik Tok by Ke$ha. (Blame It on the Alcohol)
- My Headband by Glee. (Blame It on the Alcohol)
- Get It Right by Glee. (Original Song)
- They both ran against Kurt for Senior Class President in Season Three.
- They both have gotten at least one solo in both Britney Spears tributes. In Britney/Brittany, Rachel sung Baby One More Time and The Only Exception, while Brittany sang I'm a Slave 4 U. In Britney 2.0, Rachel sung Oops!... I Did It Again, while Brittany sung Hold It Against Me and Gimme More.