They are about to go on a difficult hunt, that might cost their lives and all, and then the night before Dean and Cas are in the library with the radio on, and start some slow song, and Dean is just like ‘fuck it’, and take Cas’s hand and tells him “let’s dance”, and Cas is like “What? Dean I don’t know how to do this” but Dean says “so just move”. Dean puts one hand on Cas’s back and the other still honding his hand, Cas does the same. At some point Dean closes his eyes and one single tear escapes. Their bodies were close, they were breathing the same air, and when the song ends Cas just tightens his grip on Dean, and they continue to move slowly, because if something happened the next day, they had this moment.