Kurt runs back to New York instead of letting them talk him into marrying Blaine.
Everyone from Lima including Burt harrass Kurt so much that he winds up quitting NYADA. He hides out with Isabelle for a while. She gets him a job in London.
He doesn't tell anyone from Lima where he is going. He does give Burt and email address, but Burt passes it on to Blaine, so Kurt cuts off contact.
There was really no other pairing on the fic, but towards the end of it Kurt was hoping that he could reconnect with Adam and at least be friends with him
Found it myself. It was season five AU from right after the proposal by one of my favorite authors chocoholicannanymous