AU in which Kurt and Sebastian had met before.
Blaine and Kurt met not at Dalton, but at NYU, and started dating not long after. However, when on a break in the relationship, due to Kurt landing the once in a lifetime opportunity to work for a French designer in Paris for the summer, Kurt and Sebastian met. The designer was, in fact, Sebastian’s mother, consequently a very close friend to Blaine’s mother. The pair decided to leave their summer fling up to fate and the serendipitous chance that, if it was meant to be, they would meet each other again some day. So Sebastian went back to the University of Paris, Kurt to NYU and back to Blaine, until the day that they met again.
(Source: anderbrangst)