When the very first major superhero team, the Justice Society of America, was formed, they were very much a collection of individuals rather than a true team. Even their stories were often glorified solo features written around a framing sequence. When the Justice League of America debuted, it followed in those same footprints. These superheroes were strictly colleagues. When Marvel Comics launched its own superhero team with the Fantastic Four, however, two of the members of the team were dating (Mister Fantastic and the Invisible Girl). This was something of a game-changer.

Soon, every superhero team that Marvel launched had at least one couple on the team, which has been a constant ever since. With so much romance in the air, however, and a limited amount of available couples, that has led to a number of notable cases of unrequited love. Here, we will show you 15 instances where superheroes were into their teammates but they were instead stuck as "just friends." This, of course, just goes to show you that even the most powerful men and women in the universe can get locked into the oft-dreaded Friend Zone!

15 WOLVERINE/JEAN GREY

Probably the most famous case of unrequited love in comic book history is the one that Wolverine harbored for his X-Men teammate, Jean Grey, for years. He even technically had a chance at her when she returned from the dead and her old boyfriend, Cyclops, had re-married and had a kid while she was gone. The X-Men, however, had faked their deaths, so Wolverine did not reunite with Jean until she was already close to getting back together with Cyclops (with his wife now out of the way).

Over the years, the one-sided nature of their relationship has been retconned so that Jean was also feeling a lot of the same things about Wolverine that he felt about her. She just stuck with Cyclops and then she, well, died again. Now that she's back and he's back, maybe this will finally become requited?

14 BLACK KNIGHT/WASP

When Roger Stern took over writing duties on the Avengers in the early 1980s, he slowly but surely changed the roster of the team until he had, probably for the first time in over a decade, a roster that was almost entirely made up of characters who only appeared in the pages of the Avengers. Therefore, he could do whatever he wanted with them.

He chose to sow the seeds for the epic event known as "Under Siege," where the Masters of Evil took over Avengers Mansion. In the months leading up to it, Baron Zemo cleverly played up any rifts in the Avengers that he could exploit, one of which was the Black Knight's big time crush on the Wasp, while she viewed him solely as a friend. It distracted him at just the wrong time.

13 BATMAN/BLACK CANARY

In the history of comic books, there probably has never been a fill-in issue quite as odd as the one issue that Robert Kanigher wrote of Justice League of America while the series was transitioning from Denny O'Neil to Mike Friedrich. In his one fill-in issue, Kanigher decided to reveal that Black Canary's sonic scream also gave her telepathic abilities for some reason.

Not only that, but he also decided to reveal that despite Black Canary and Green Arrow clearly already establishing a romance, that Batman was into Black Canary, as well. They even shared a kiss! Freidrich had to quickly put this plot down by revealing that Canary only saw Batman as a brother. It was definitely one of the oddest short-lived love triangles in Justice League history.

12 NAMOR/INVISIBLE WOMAN

Jack Kirby image of Namor carrying Sue Storm, pursued by the Fantastic Four in Marvel Comics

It is hard to call the feelings that Namor had for Invisible Woman as necessarily "unrequited love" when the guy just flat out kidnapped her a bunch of times. That's not romance, that's a felony! However, at the same time, Invisible Woman (he had been kidnapping her for so long that when he first did so, she was still going by "Invisible Girl") could not help but admit that she felt something for Namor, as well.

This was a major plot point when Mister Fantastic was thought to be dead and Namor effectively joined the Fantastic Four in his place (so did Ant-Man, so it was unclear who was technically the fourth member of the group), and he and Sue Richards almost pursued a romance further. It never happened and then Reed Richards turned up alive.

11 PSYLOCKE/CYCLOPS

A particularly strange case of what appeared to be unrequited love occurred when X-Men and X-Factor merged together to form one giant team of X-Men, which was then split into two teams, a Blue Team and a Gold Team. The Blue Team appeared in a spinoff title, X-Men, which was written and drawn by Jim Lee. Lee, in effect, got the first pick for his team and took most of the most popular members of the X-Men at the time (Wolverine, Gambit, Rogue, Cyclops, Beast and Psylocke).

Jim Lee was prone to drawing Psylocke in swimsuits a lot and during his run, he had Psylocke flirt heavily with Cyclops, who was in a serious relationship with Jean Grey (they would marry in X-Men #30). By flirting heavily, we mean she would suggestively lick her fingers in front of him. It never went anywhere, but she sure laid it on thick.

10 FLASH/ZATANNA

Zaranna flirts with Barry Allens Flash

Unlike the Avengers, Justice League of America rosters rarely had characters on the team who did not have their own feature in some other title (even if it was just a back-up feature). A notable exception joined the team in the late 1970s and that was the magician known as Zatanna. Justice League of America was the only place you could get your backwards magic fix for years.

After the Flash's wife died, writer Gerry Conway began a flirtmance between Barry Allen and Zatanna. It even seemed to get more than just flirting when they had dinner together in Justice League of America #187. It never went any further than that, though, and Barry soon was engaged to another woman. It made for a tense monitor duty period for a little while there, though.

9 BLACK KNIGHT/CRYSTAL

The perpetual sad sack of the Avengers, Black Knight, was at it again in his second extended tenure with the Avengers in the early 1990s. When Bob Harras began his run, he also made sure to make it so that almost all of the members of the team appeared only in the pages of the Avengers. He then ramped up the soap opera drama heavily.

The centerpiece of the drama was a rarity in comics: a love rectangle, as the married (but separated) Crystal joined the team while on the outs with her husband, Quicksilver (who was on X-Factor). Black Knight longed for Crystal, but she didn't feel right about it. Sersi, meanwhile, was into Black Knight and they began dating, even though he clearly pined for Crystal. This time around, Crystal and Black Knight did at least kiss, but they ended up apart in the end.

8 MAXIMA/SUPERMAN

Like Namor, the relationship (if you would call it that) between Maxima and Superman was more on the creepy stalker side than necessarily being an "unrequited romance." Maxima was an alien who showed up on Earth and decided that she had to mate with Superman for the good of her world. He was not interested and she did not respond to "no" very nicely.

However, rather than becoming an outright villain, she instead joined the Justice League when Superman took over the team so that she could possibly change his mind. It never happened, but she surprisingly ended up being a decent member of the team for a few years (before eventually returning to more explicit villainy when Superman got married). She eventually heroically sacrificed herself during the Imperiex War.

7 SCARLET WITCH/CAPTAIN AMERICA

As noted earlier, Stan Lee was all about interpersonal relationships when he established the Marvel Universe along with his many classic artists like Jack Kirby and Steve Ditko. The Avengers, though, were initially very much in the mold of the Justice League of America. A bunch of Marvel's characters who had their own features would join together and fight crime. After a little over a year of this, however, Lee wanted a different approach. He got rid of all of the members except for Captain America. He then added three reformed supervillains to the team.

The three reformed supervillains (Hawkeye, Scarlet Witch and Quicksilver) all intermingled with Captain America in different ways. In the case of the Scarlet Witch, she developed a big crush that never went anywhere. Years later, Captain America had a brief relationship with a magical version of the Scarlet Witch (don't ask).

6 FLASH/POWER GIRL

Power Girl pursues Wally West Flash

When Wally West took over as the Flash for Barry Allen following Crisis on Infinite Earths, writers had a difficult time writing for Wally. The only extended characterization that he ever really received was during Marv Wolfman and George Perez's New Teen Titans, and there he was basically "the conservative guy."

Now that he was the Flash, however, writers tended to lean on him being a bit of an immature jerk. That was how he was presented in Justice League Europe, where his uncle's old friend, Elongated Man, was always sure to remind him of the past. While on the team, Wally flirted constantly with Power Girl in a manner that never would be seen as okay nowadays. The relationship never went anywhere and Wally eventually found real love with Linda Park.

5 HAWKEYE/SCARLET WITCH

Like we mentioned earlier, the "Captain America and three reformed supervillains" routine (retroactively referred to as "Cap's Kooky Quartet") in the Avengers was all built upon interpersonal connections. Hawkeye thinks that he would make a better leader than Captain America. Quicksilver feels that his powers are better than everyone, Scarlet Witch pines for Captain America, so on and so forth.

While Scarlet Witch was crushing on Captain America, Hawkeye was crushing on Scarlet Witch, as well. Then, Hawkeye's former love, Black Widow, was willing to switch to being a hero, as well, so Hawkeye forgot about Scarlet Witch. When he returned to show an interest with her later on, she had already moved on with the Vision. Hawkeye just had rotten timing with it all.

4 CHANGELING/TERRA

One of the saddest cases of unrequited love between superheroes on this list is that between Changeling and Terra. Changeling, you see, was the youngest member of the New Teen Titans and so when a girl his age joined up, he was ecstatic! Terra, though, did not seem that interested in him. He seemingly began to wear her down with his sheer enthusiasm and they even ended up sharing a kiss.

Of course, as it turned out, Terra was a double agent the whole time and was spying on the team for Deathstroke the Terminator. She was a villain, through and through, and died in battle against the Titans, never showing a glimpse of being anything other than a damaged and cruel young woman. It was very difficult for Changeling to handle.

3 MANTIS/VISION

While the Vision/Scarlet Witch romance had actually been introduced by Roy Thomas before Thomas left the Avengers when he became Marvel's Editor-in-Chief, it was Steve Englehart who did the most work with the romance between the two. Englehart, though, made things a bit more interesting by introducing a third wheel to their romance in the person of Mantis.

Mantis was a mysterious new hero who joined the Avengers alongside her boyfriend, former Avenger foe, the Swordsman. He was reformed and in love with Mantis, but she soon seemed to have eyes only for the Vision -- as she would put it, "This one loves the Vision." She loved to refer to herself as "This one" for... reasons? In the end, though, Vision ended up marrying the Scarlet Witch and Mantis married an alien who took on Swordman's appearance after Swordsman died. Comic book romance is strange.

2 BATMAN/WONDER WOMAN

During Joe Kelly's run on JLA, he slowly brought in some aspects of the then-popular Justice League cartoon, like John Stewart and Hawkgirl both joined the team, just like they did on the show. Plus, just like the show, he began to introduce a possible romance between Batman and Wonder Woman. At one point, when they were about to die, Batman even kissed Wonder Woman!

In JLA #90, Wonder Woman uses a special machine to see possible futures based on the possibility of she and Batman getting together. As it turned out, none of them really worked out, as either she would become too dark because of him or he would be unable to adjust to her world of the gods. So, in the end, they decided that it was best to remain "just friends."

1 BLACK WIDOW/CAPTAIN AMERICA

Perhaps the strangest case of unrequited romance between Avengers teammates occurred in the mid-1990s when literally, out of nowhere, Black Widow began to have feelings for Captain America. We're talking intense feelings here, like sitting around and watching him sleep type feelings.

The reason why this was particularly strange was because of the timing. Captain America was currently dying in the pages of his comic book series, as his Super Soldier Serum had turned against him. Obviously, he was going to be cured, but the cure was going to lead into Mark Waid's then-new run on the series, so clearly Cap was not available for a romance in the pages of the Avengers. And yet the start of one happened anywhere. It was utterly bizarre.