Eventually, Kurt asks Blaine what the problem is, resulting in Blaine telling him that he was with someone else back in Lima (presumably Eli. Kurt leaves heartbroken and ends up giving him the silent treatment.
In The Role You Were Born to Play, Blaine admits to Sam that since the break-up, he hasn't been the same and is afraid that he lost the love of his life.
Blaine then asks the New Directions, The Warblers, the Haverbrook School for the Deaf and Vocal Adrenaline to aid him in his proposal to Kurt by singing Help! Burt drives Kurt to Dalton Academy, where Blaine and all the choirs proceed to sing All You Need Is Love, along with Rachel, Mercedes and Santana, before finishing at the very staircase on which Kurt and Blaine first met.While Kurt remains in love with Blaine, the latter has begun dating David Karofsky.They eventually reconcile and spontaneously get married in a double-ceremony with Brittany Pierce and Santana Lopez.Kurt and Blaine make up in Thanksgiving, and then as a Christmas present, Burt brings Blaine to New York in Glee, Actually, and, while ice skating, Kurt and Blaine duet White Christmas.At the end of the season, Kurt arrives in Lima to support his dad at his appointment, having recently found out that Burt has stage 1 cancer, and visits Mc Kinley with Mercedes and Mike to see the New Directions.The couple break up in The Break-Up, but they started dating again in Love, Love, Love, where Kurt accepts Blaine's marriage proposal.In New New York, Blaine moves to New York to live with Kurt, but they soon realise that their relationship is stronger if they live separately, and he moves out.Blaine gives Kurt advice on how to handle 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, resulting in him and Blaine continuing to grow closer.Blaine often acts as a mentor and source of courage for Kurt, before making the transition into a romantic interest.Blaine gives a heartwarming speech about his and Kurt's love, before asking Kurt to marry him, which, through tears, Kurt agrees to.After graduation, Blaine gets accepted into NYADA and moves in with Kurt in New York.