Surprise JDM
From Super-wiki
Along with the Spanish Inquisition, no one expects Jeffrey Dean Morgan.
Sometimes written as Surprise!JDM, Surprise JDM is said to occur when Jeffrey Dean Morgan appears and has sex with either Jensen or Jared or both in a RPF story, without warning through the pairings listed in the header of the fic. People who are heavily invested in the OTP can find this distressing. Warning for Surprise JDM is advised.