I'm looking for an AU, but I'm vague on some details. Blaine is a teacher in CA somewhere. He lives with a roommate who has a girlfriend. Blaine and Kurt meet in California I think they start dating but Kurt returns to NY leaving no contact info. Some time later Blaine follows after Kurt with no other plan but to find him, leaving his roommate (Robbie? maybe?). Blaine cannot find Kurt in part because Kurt has protective pushy friends who think Blaine wasn't good to/for him and so put Blaine off instead of helping him find Kurt. Not to mention Kurt has at approximately the same time gone back to CA to find Blaine.
Blaine gives up, finds a temp teaching in Brooklyn (?) and ends up helping his kids with a small annual fashion show that Kurt's magazine always does a little piece on and last minute it's Kurt who goes to the school and to his surprise finds Blaine.
They do end up together, I believe that they end up adopting a kid that Blaine connects with from his class who Kurt is uncertain of because of his trauma history and Kurt is concerned that their adopted daughter will be negatively affected by the new addition.
I may be confusing a second story when it comes to the adoption piece but I'm pretty sure that either in the story itself or a follow up oneshot the family (Klaine + the 2 kids) go to Disney and Kurt ends up chatting with a random Mom who complements him on his beautiful family and I'm pretty sure she ends up being the roommate's wife, there with the roommate, now her husband and father to her two children.