It's Insanity, but...
The doorbell interrupts what had turned out to be quite the epic shoe hunt but, really, he’s grateful for the break. Or at least, he is until he heads down the stairs to grab the door, trips over a stuff animal of some kind, bashes his head on the wall and barely manages to catch himself from falling down the entire flight of stairs. As with all things, Stiles would like to state, for the record, that this is Scott’s fault.
Or: Scott and Stiles are raising seven children. Derek is the entertainer they hire for a birthday party (not a clown though, he's very specific on that fact.)