I'm looking for a Puckurt fic, I thought it was this:
but it is not. Puck and Kurt are together for a long time, probably married. Puck sleeps with the mother of one of his students, I think he teaches piano or music. He and Kurt stay together after this. That's all I remember.
So, purely by happenstance I found this fic that I was looking for. I was just reading some old faves, then went to their list of fave stories to read some of those and found this in debraelq's list of favorite stories:
It's no wonder I didn't remember much more, it's conversations between Kurt and Burt over the years.