One of the most underrated romances Captain America ever shared was sadly never brought to life in the Marvel Cinematic Universe. Sure, most fans were hardcore shippers of Steve Rogers and his greatest love, Peggy Carter, but that dedication prevented him from ever getting to know one obscure, but equally powerful, relationship from the comics.

Despite the Marvel Cinematic Universe’s focus on Steve and his relationships with not one, but two Carter women, there was someone else from the comics who from the Serpent Society began as merely an antagonist for Marvel’s patriotic superhero. But after just one encounter, Diamondback found herself falling for Captain America and the two had a thing throughout the ‘80s and ‘90s. While it never lasted, Diamondback was a big part of Captain America’s lore, yet her romance with the iconic Marvel hero was tragically ignored in favor of Peggy Carter.

The Origin of Captain America's Forgotten Love Interest, Diamondback

How She and Cap's Surprising Romance Blossomed

Captain America has faced a lot of villainous organizations in his incredibly long life. But beyond AIM and HYDRA, Steve found himself going up against a new collection of foes in the mid ‘80s. They were the Serpent Society, and they would work for supervillains, but on a united front with one another, like a labor union. The society was composed of multiple snake-themed villains such as Sidewinder, Cottonmouth, Constrictor, and of course, Diamondback. It wasn’t long before the Serpent Society came across Captain America, and Diamondback fell for the hero instantly.

The Serpent Society first debuted in Captain America #310!

Diamondback, or Rachel Leighton, stayed with the Serpent Society for a few years, but her interest in Captain America only grew. She even aided Captain America in several confrontations with a few of his iconic enemies, like Batroc the Leaper or Baron Zemo. While cautious, Captain America didn’t shy away from Rachel’s feelings and engaged with her. The two even dated for a short period of time. While the two began fighting crime together, their whirlwind romance ended almost as quickly as it began.

...a small rift between Rachel and Steve as Diamondback still had friends in the society she was still loyal to.

Diamondback was eventually put on trial by the Serpent Society for her relationship with Captain America, as it was feared she'd given away sensitive information about the Society. The trial created a small rift between Rachel and Steve as Diamondback still had friends in the society she was still loyal to. But that rift was small potatoes compared to when Diamondback accidentally killed the villain Snapdragon after Rachel became unstable from being dosed with Rogers’ blood. While the two remained friendly, their romantic life was over.

Why Captain America's Time with Diamondback Never Got to Feature in the MCU

The Franchise Chose to Emphasize Peggy (And Only Peggy)

Granted, as much as the Marvel Cinematic Universe uses the source material to help construct its universe, the films aren’t a 1:1 adaptation. After all, the comics go back decades and there are hundreds of pages worth of stories, whereas the MCU only has a couple of movies for each character. So when it came time to tell Captain America's story, there was only time to really have him meet and fall for one character, his World War II-era love, Peggy Carter.

Of course, Steve and Peggy’s relationship was put on the back-burner after Cap came to the modern era, but his heart still belonged to his lost love. To the MCU’s credit, it did attempt to give Steve his love interest from the comics, Peggy’s niece, Sharon Carter. However, their romance was barely touched upon outside a few charged moments. And as all fans , by the end of Endgame, Captain America used time-travel to go back several decades and live out a full life with Peggy.

... the Serpent Society was heavily scaled back to just Sidewinder and Copperhead with Diamondback’s material cut out of the film altogether.

In the MCU, fans didn’t even get a chance to meet the Serpent Society until late in the game, as they didn’t even appear until Captain America: Brave New World. Aside from the fact that Steve was retired at this point, the Serpent Society was heavily scaled back to just Sidewinder and Copperhead with Diamondback’s material cut out of the film altogether. While the MCU has done its best to adapt other key components of Captain America’s lore, his relationship with Diamondback wasn’t big enough to bring onscreen.

The Diamondback/Captain America Ship Was the MCU's Biggest Missed Opportunity

It's Too Late to Show Off Steve's Most Complicated Love Story

It’s understandable why the MCU skipped over this relationship. For one, fans really grew attached to Peggy, and they didn’t want to see Steve with anyone else. Hell, his relationship with Sharon never went further than a kiss in Captain America: Civil War, so it was unlikely fans were ever going to see him playing the field more than that. But it’s a real shame that the franchise skipped this storyline, because it shows that love can be complicated, even for someone so pure like Captain America.

... love can happen between anyone, even people who might be on the opposite sides of the villain/hero dynamic.

Captain America is about as close as one can get to a saint among superheroes. While many may expect better of him than to date a supervillain, he’s a human like anyone else. The comics showed that love can happen between anyone, even people who might be on the opposite sides of the villain/hero dynamic. Unfortunately, the MCU wanted its Captain America to have as little messiness or drama as possible. Defending Bucky in Civil War was one thing, but having him date a villain would have been a bridge too far for the MCU.

It’s too late now for the MCU to showcase Captain America and Diamondback’s relationship. But it’s important to acknowledge that, for a time, Steve did have feelings for a villain and that his relationship started to have a positive impact on her life. While MCU fans will never get to see that, it still exists in comic canon and no amount of ignoring it will undo it. For better or worse, Captain America cared about Diamondback, and while the MCU preferred to ignore it, it’s an interesting, if overlooked, part of his history.