Deb and Dexter always had a close relationship, one that Dexter never really had to fake or use as a cover story in his life - he truly felt connected to Deb as his sister. ... After a string of failed relationships, Deb realized in therapy she didn't just love Dexter as a brother, she was in love with him.

Do Deb and Dexter sleep together?

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.

What episode does Deb fall in love with Dexter?

In the series' final episode, "Remember the Monsters?", Debra is taken to the hospital, where she tells Quinn she loves him and wishes Dexter a happy life.