Rebel

Cas, Sam, and Dean are working a case. Cas has to go undercover as a priest and ends up doing a sermon... unbeknownst to him, Dean takes a not-so-heavenly liking to him in a priest outfit. Priest!kink-ish. Pointless smutt. Church sex. Top!Dean, Loud Bottom!Cas. Dirty talk, a bit. Established Destiel.