Samwitch
From Super-wiki
Samwitch is the portmanteau name for fanfiction pairing the characters Sam Winchester and Rowena in a romantic or sexual relationship.
The pairing was sparked after Sam sought Rowena's help in decoding the Book of the Damned [1][2][3]. Years later, when Rowena resurrects herself after being killed by Lucifer, she and Sam form a bond over their shared torture at his hands. [4]