Jack's 'Mom-side' of the family is terrible, far as Lucifer is concerned. The human in him is what ruined all of Lucifer's clearly well-thought out plans. There should've been no other problem. He played all the cards right.

(Jack called him a monster and still brought Lucifer back for this playdate.

The hell did that even mean.)

"Oh, don't worry, I'd assume you would never willingly be in the same room again with--what was it..." He takes a second to look like he's remembering even though it is so extremely burned into his being. "... 'the first few cells of cancer.'"