The first fic I read recently. I can't remember if it was a oneshot or part of a collection of oneshots. I think it was told by Kurt's son and it was about Kurt shaving his head in memory of Blaine who had died of cancer when Klaine was 18.
The second fic I read a while ago. In it Kurt finds out that Blaine has a large number of brother, all of whom go to boarding schools or work around the country. Cooper was the oldest. There were at least 2 sets of twins, including Blaine.
*Second fic found. Still looking for the first.