Crowley (to Rowena): Mother.

Louis: “Mother”?

(Crowley blows Louis into pieces)

Rowena: That is the sweetest thing you’ve ever done for me.

From Supernatural – Season 12 Episode 8: ‘LOTUS’ (12×08) | TV series produced by The CW



Quote meaning
Louis was Rowena’s latest date – fiencé actually. But she just found out he’s a scammer. That is why she wasn’t mad, that Crowley killed him.