Okay so I'm looking for two different fics..
1. Soulmate!klaine (famous Blaine maybe?)
I remember Blaine attending an event that I think vouge was holding (Kurt works there?) and Isabelle get's excited saying "he never comes to these things" and then Kurt is all "oh this is actually my soulmate". There might be an age gap as well?
FOUND: You Make Me Feel So Young by chatterboxrose
2. This one Kurt and Quinn have a baby together. I remember that They keep it and Burt and Carol adopt the baby. Later on I remember that Kurt starts dating Blaine and he first introduces the child as his brother but later on tells Blaine that's it's actually his. (In the last bit they come visit from New York with their child?)
FOUND: here(thanks in advanced!)