Klaine

"Blaine, I’m a man who’s always lived in the shadows. And everyone who’s come into my life has always tried to pull me out into the sun or push me back into the darknes; and then you came along. And even if someone had told me that it wasn’t gonna work out and that at the end of all of our struggling and all of our work, it would just end in heart ache. I'm a working progress."

- Kurt's vows towards Blaine on their wedding day Klaine is the slash ship between Kurt Hummel and Blaine Anderson from the Glee fandom.

Canon
The first meeting of Kurt and Blaine takes place in the episode "Never Been Kissed", when Kurt is "forced" by Puck to spy on the rival choir: the Dalton Academy Warblers, after the meeting with the boys to talk about the challenge: Boys vs. Girls. Kurt is caught by Blaine and two other Warblers, Wes and David, where Kurt thinks it is nice of them to buy him coffee before beating him up. Blaine and Kurt have instant chemistry and soon develop a friendship. Blaine advises Kurt on how to deal with Karofsky's bullying and goes to Kurt's school to confront Karofsky about his actions, but when the bullying becomes unbearable, Kurt transfers to Dalton Academy and joins the Warblers in "Special Education", which causes him and Blaine to grow even closer. Blaine often acts as a mentor and source of courage for Kurt, before transitioning into a romantic interest.

In "A Very Glee Christmas", Kurt reveals to Will that he is in love with Blaine, and that Blaine is actually gay. The two perform their first duet, Baby, It's Cold Outside. Then, in "Silly Love Songs", Kurt admits to Blaine that he has feelings for him after Blaine fails to serenade a guy he likes in "the Warblers Gap Attack". Blaine confesses that he has no idea what he is doing when it comes to romance, and the two agree to remain friends. They remain just friends until Blaine realizes that he is in love with Kurt in Original Song (when Kurt sings Blackbird by The Beatles). This is the episode in which they share their first kiss, and it is assumed that they start dating soon after. In the episode "New York", Blaine tells Kurt that he loves him for the first time, to which Kurt replies that he loves him too.

Their relationship is taken to the next level in season three when Blaine joins McKinley and the New Directions because he can't stand being away from the person he loves.

Kurt and Blaine share loving glances during some songs and rarely fight, having only fought three times during their relationship so far (The First Time, Dance with Somebody and The Break-Up). They have been dating for over a year and celebrated their one year anniversary was on March 15, 2012. They also lost their virginity to each other in "The First Time". Towards the end of the year, Blaine and Kurt are dismayed by the idea that Kurt will graduate and move to New York while Blaine will be left behind for another year. However, they insist on always being together.

Kurt and Blaine's relationship is put to the test when Blaine convinces Kurt to move to New York, by singing It's Time to him in "The New Rachel". At first, they successfully maintain their long-distance relationship by Skyping and texting, but with conflicting schedules, things quickly start to fall apart. In "The Break-Up", Blaine surprises Kurt by showing up in New York early. During Blaine's acoustic performance of Teenage Dream, he becomes very emotional, which Kurt notices. Eventually, Kurt asks Blaine what the problem is, and Blaine tells him that he was with someone else in Lima (presumably Eli.C). Kurt leaves heartbroken and ends up giving him the silent treatment. In "The Role You Were Born to Play", Blaine admits to Sam that, he hasn't been the same since the breakup and is afraid that he has lost the love of his life. Kurt and Blaine make up at Thanksgiving, and as a Christmas present, Burt brings Blaine to New York in Glee, Actually, and Kurt and Blaine duet White Christmas while skating. At the end of the season, Kurt arrives in Lima to support his father at his appointment, having recently found out that Burt has stage 1 cancer, and visits McKinley with Mercedes and Mike to see the New Directions. Blaine flirts with Kurt, and in "Wonder-ful" Blaine asks Burt for permission to ask Kurt to marry him. Burt, while happy that Blaine is so in love with his son, tells Blaine that they are too young and that they are meant to be together, so he should just relax and everything will be fine.

In "Love, Love, Love", Blaine convinces Kurt to get back together with him after finding out that the relationship between Kurt and Adam Crawford didn't work out, after which they sing Got To Get You Into My Life, a song prepared by Kurt and performed with a marching band. Blaine then asks the New Directions, the Warblers, the Haverbrook School for the Deaf and Vocal Adrenaline to help him propose to Kurt by singing Help!, which they all happily do. Burt drives Kurt to Dalton Academy, where Blaine and all the choirs join Rachel, Mercedes, and Santana in singing All You Need Is Love, ending on the very steps where Kurt and Blaine first met. Blaine gives a heartwarming speech about his and Kurt's love before asking Kurt to marry him, which Kurt tearfully agrees to. After graduation, Blaine is accepted into NYADA and moves in with Kurt in New York.

Their relationship is once again tested by their new lifestyle and Kurt's newfound confidence, which puts them in an uncomfortable position, and Blaine finally decides to move out to draw boundaries between them and learn how to live in the big city. After a while, when Rachel moves to LA, Blaine moves back in with Kurt and they live together in the loft. Blaine and Kurt broke up sometime before the season started. Their constant fighting led Kurt to believe that they were not meant to be and he broke off their engagement. Blaine then returned to Lima after his depression caused his grades to drop and he eventually dropped out of NYADA.

Kurt finally realizes his mistake and rushes back to Lima, hoping to earn Blaine's forgiveness. Much to his disappointment, Blaine is already seeing someone: Karofsky. With Sue's help, they finally realize their lingering feelings for each other. While originally helping out at Brittany and Santana's wedding, the brides and Sue convince them to hijack the wedding and get married alongside them.

Blaine eventually moves back to New York to attend NYU, while Kurt goes back to NYADA. Five years later, they are now successful actors and parents, with Rachel as their surrogate.

Fanon
Klaine is the most popular ship in the Glee fandom. Originally featured as a secondary ship, Kurt and Blaine's relationship took center stage in later seasons, and along with Brittana, they carried the show on their backs. On AO3, Klaine is the most written about ship within the Glee tag; Kurt's most written about as well as Blaine's most written about.

Fandom

 * FAN FICTION
 * Kurt/Blaine tag on FanFiction.Net
 * Kurt/Blaine tag on FanFiction.Net


 * TUMBLR

Trivia

 * Both have had crushes on other boys on the show before dating: Kurt had crushes on Finn and Sam, and Blaine had a crush on Jeremiah.
 * In "The Purple Piano Project", Kurt mentions watching "The Bachelorette" with Blaine.
 * In much of the fandom, kissing, cuddling, and sex between the couple are known as "Klisses," "Kluddles," and "Klex," and now "Kledding".
 * Both are each other's first boyfriend.
 * Both had moved to Dalton because of severe bullying.
 * In "I Kissed a Girl" Blaine mentions that the couple likes to sing Pink's song Perfect together in the car.
 * They both love Vogue, Marion Cotillard, fashion and musicals.
 * Blaine has a picture of Kurt on his nightstand, first seen in "Michael".
 * Both kiss a girl before their relationship: Kurt kisses Brittany in "Laryngitis" and Blaine kisses Rachel in "Blame It on the Alcohol".
 * "The First Time" is the first episode in which Blaine calls Kurt his boyfriend.
 * They both have pictures of each other in their lockers. In "Never Been Kissed", Kurt has the word COURAGE made out of magazine letters, with a picture of Blaine in his Dalton uniform above it. In "Big Brother", you can see a poster from Kurt's campaign for class president in Blaine's locker.
 * In "Dance with Somebody", Kurt explains that he and Blaine plans to make out.
 * In "Dance with Somebody", when Blaine says, "I love you so much," he is wearing the same cardigan he wore when he first told Kurt he loved him in New York.
 * Rachel and Santana indirectly sang a duet about how Kurt or Blaine feels while talking to the other guy; A Boy Like That/I Have A Love for Blaine and Sebastian and So Emotional for Kurt and Chandler.
 * They apparently watch a lot of reality TV shows together, including "The Bachelorette", "Being Bobby Brown" and "Jersey Shore". As shown in "Props", they also went trick-or-treating and dressed up as Snooki and The Situation.
 * In "Extraordinary Merry Christmas", Blaine had saved Kurt's favorite gum wrapper so that he could make it into his promise ring to give to Kurt. Since this was deleted content and not in the actual episode, it was considered non-canon, until a scene in "Dreams Come True", where Kurt shows Blaine his time capsule locker and that he had kept this ring.
 * Both ran for Senior Class President their senior year. Kurt lost, but Blaine won.
 * It was implied that Kurt picked out some of Blaine's clothes in "Big Brother", "Movin' Out", and again in "New New York".
 * Blaine has a scrapbook with pictures of Kurt as seen in "The Role You Were Born to Play".
 * Both had a crush on Sam: Kurt in "Duets" and Blaine from "Sadie Hawkins" to "Guilty Pleasures".
 * Both have performed a song with the New Directions Girls while wearing an elaborate costume. Kurt, Bad Romance and Blaine, Diva.
 * Santana said in "Girls (and Boys) on Film" that Come What May is the song they want to sing at their wedding.
 * They had a duet in three of the Christmas episodes: "Baby, It's Cold Outside" in Season 2, "Let It Snow" in Season 3, and "White Christmas" in Season 4.
 * All three songs Blaine sings in the courtyard are for Kurt.
 * In "I Do", they have sex in hotel room number 206, similar to "Never Been Kissed" (2.06), the episode where they first meet.
 * In "Love, Love, Love", Kurt and Blaine share a kiss in the courtyard after singing Got to Get You into My Life, the first time they openly kiss at McKinley High School.
 * They get engaged on the same staircase where they met.
 * They are the second young couple to get engaged on the show after Finchel.
 * They are the only couple on the show to get back together and get engaged in the same episode.
 * They are also the only couple to get back together and get married in the same episode.
 * "Klaine" was nominated for a People's Choice Award (2014) for Favorite On-Screen Chemistry.
 * Both were part of the Cheerios at some point. Kurt was a Cheerio member during the first season, while Blaine was a Cheerio member during the fourth season.
 * In "The Back-Up Plan", they share more kisses and "I love you's" than any other couple in a single episode.
 * In season five, they share more kisses than in all previous seasons combined.
 * Their kiss in "The Hurt Locker, Part Two" lasts longer than any other kiss in the series.
 * Kurt and Blaine have the same anniversary as Santana and Brittany because they were married on the same day.
 * Their first kiss was included in Glee's Top 5 On-Screen Kisses countdown.
 * They were included in Glee's Top 3 Unsinkable Ships countdown.
 * They made it to the top four of E! Online's TV's Top Couple Tournament in 2015, but lost to Killian Jones and Emma Swan from Once Upon a Time.
 * They are the second couple (after Finchel) with the most duets.