Blaine, Puck, Finn, Quinn, Tina (maybe more? Can't remember) are all werewolves. Kurt is a normal human, but due to Finn he gets pulled into the werewolf world. He and Blaine are in an established relationship and they decided to progress to full on mates, which is a bit of a trial since Kurt's still fully human and the rest of the pack isn't quite cool with that. Puck is very protective towards Kurt and Blaine, I'm pretty sure Quinn was pregnant (she and Puck were together)... And that's about all I remember.
Anyone care to help a sister out?