Alex:
Claire. You know I don’t do that anymore. Claire:
I need your help... Alex:
I said no. Claire:
Let me rephrase, Jody’s on a hunting trip, and she hasn’t been home in a few days.
Dean attempts to rickroll Cas, but Cas doesn’t realize it’s supposed to be a joke, and so he responds earnestly to what he thinks is Dean’s genuine (albeit horribly musically passe) declaration of undying love.