Their bond may have extended beyond the normal sibling relationship, but it was their everlasting platonic love in Dexter's season 8 finale that allowed them to move on, with Dexter finally saying the words “I love you” allowing her to die, and Deb's death being the catalyst for Dexter to abandon Hannah and Harrison.

Did Deb and Dexter hook up?

When that revelation stirred up some jealous feelings, Deb finally confessed to Dexter that she's in love with him. So we now have a brother-sister-serial-killer-cop-other-lady-serial-killer love triangle on our hands. To recap: Dexter was going to kill Hannah, then he decided to have sex with her instead.

Does Debra Morgan fall in love Dexter?

At the end of the season, her therapist helps her realize that she has been in love with Dexter all along. She finally makes peace with the idea — on the same day that she catches Dexter in the act of murdering "Doomsday Killer" Travis Marshall (Colin Hanks).