There are a lot of shocking factors to Showtime's Dexter, but the serial killer series found a way to take things too far with perhaps Dexter's most disturbing plot twist... Debra's 'incestual' love for Dexter.

Fans were finally treated to a moment they had been waiting for since the beginning of Dexter, when, during the season 6 finale in 2011, Deb discovered Dexter's true nature and learned about his dark passenger. However, this big moment was somewhat diminished by the shocking news that Deb was also in love with Dexter, her adopted brother.

In the following, we take a look back at why Deb being in love with Dexter became one of Dexter's worst storylines and how it changed the trajectory of the series. We also reveal how the Dexter cast felt about the "incestual" love storyline in Dexter.

Why Dexter's Storyline Of Deb Being In Love With Dexter Is One Of Its Worst

Making a storyline out of Deb's romantic love for Dexter has divided more fans than Dexter's controversial series finale. The show's series finale is often remembered poorly and has been called "terrible" and a "disgrace." Fans just didn't feel like it was a proper sendoff to their favorite serial killer. However, ruining the brother-sister bond between Dexter and Debra Morgan was basically pointless to the overall plot of Dexter.

Although Deb and Dexter are adoptive siblings and not biologically related, Dexter and Deb did grow up together as siblings, so pushing for a romantic relationship between the two characters was off-putting.

Dexter Morgan was three years old when Detective Harry Morgan found him at a crime scene and took him in as his own son. Dexter was officially adopted into the Morgan family when he was seven years old, and he is Debra Morgan's older adoptive brother.

This taboo incest plot on Dexter didn't work at all. Dexter and Deb's relationship as adopted siblings was "the single most important relationship on the show," and Deb's confession that her feelings for Dexter are sexual, "totally ruins that bond for fans who've become invested in it." This unnecessary twist takes away from the event that "the series had been building up to since it began," which was Deb finding out that Dexter is a serial killer all along.

Buzzfeed describes Deb's feelings for Dexter as : " It was icky and embarrassing, the culmination of six seasons of Deb getting f**ked over by the writers. Thankfully, this plot was mostly abandoned once Debra learned her brother is a serial killer."

Dexter showrunner, Scott Buck, was quick to defend the show's decision to move forward with this controversial and confusing storyline between Deb and Dexter.

"It’s funny to me that people can accept the fact that Dexter is a serial killer without question but the minute his sister falls in love with him, it’s love that makes people go, “Ew,” and not the killing."

"Could we have done without it? Certainly, but we chose to do it because it seems inherent in this character that she has these feelings for her brother that have been there all along that she has not fully dealt with," he shared with The Hollywood Reporter. "It seemed to make the story that much more interesting and dynamic if you can intertwine them that way."

How Deb's Feelings For Dexter Changed The Series

Though Debra's romantic feelings for Dexter felt like they came out of nowhere and ruined the brother-sister bond between the two main characters, there was a reason Dexter creators went forward with this storyline and, to some fans, it actually made sense looking back at how much Deb admired her adoptive brother. During the season 6 finale, shortly after Deb comes to realize and speak aloud her romantic feelings for Dexter, she finds him in a compromising position with the Doomsday Killer, Travis Marshall.

Debra, a decorated detective for the Miami Metro Police Department, immediately wanted to call Marshall's death into the police station. However, her true feelings for Dexter prevented her from turning in her adopted brother. But fans were quick to point out that her sibling bond with Dexter meant she always loved Dexter and could have also worked in the same manner.

"It just seemed a more interesting story that at the same time she realizes she has these deeper feelings for her character suddenly coming face to face that this is not exactly who she even thought it was that she’s in love with; who she thinks her brother is, but that’s not who her brother is at all," explained Buck.

Debra finding out about Dexter's secret in the same breath as realizing her romantic love for her brother meant she would do anything to protect him. Debra began to prove this point during season 7, when she began acting out of character, becoming Dexter's accomplice and eventually even killing Maria LaGuerta to protect Dexter's secret after LaGuerta discovered Dexter was the real Bay Harbor Butcher.

Dexter And Deb's Actors Were Okay With The 'Incest' Storyline

Debra and Dexter Morgan's 'incest' storyline rubbed a lot of fans the wrong way, but Dexter's showrunners stood by the bold choice and had even thought about it for a long time before putting it into the show.

"It’s actually an idea that’s been discussed in the writers room years ago, like starting in season 2, because it always felt it — that this character was in love with her brother," stated Scott Buck in an interview with Entertainment Weekly. "And like Debra, we ignored it for a long time and it just kept coming back until we were all in agreement that it was just in the DNA of that character of why she was the way she was."

"It felt like it was finally time to tackle that issue."

Michael C. Hall and Jennifer Carpenter, who play Dexter and Debra Morgan, had to be on board to act out this controversial Dexter storyline, but according to Buck, it was never really an issue for Dexter's stars.

"They were fine with it. They knew it was a big storyline, but had no objections to it whatsoever. They knew it’s part of the show, and are obviously professionals, and would go wherever the character takes them."

The stars behind Dexter and Debra Morgan , Michael C. Hall and Jennifer Carpenter, actually dated and were married for a short period of time in real-life. Shortly after meeting, the pair began dating and eloped in 2008. Carpenter and Hall filed for divorce in 2010 and continued starring in Dexter together until the final season.