Mark Sloan and Lexie Grey's relationship became one of the most beloved pairings in the Grey's Anatomy universe. Despite the fact that many late-comers to the series like Jo Wilson, Nurse Bokhee, and the Mercy West transplants (April Kepner and Jackson Avery) have appeared on more episodes than both Mark and Lexie, their tragic ending has made the couple's love story all the more compelling. The on-again, off-again pair were apart more often than they were together, but something about the chemistry between actors Chyler Leigh and Eric Dane made Lexie and Mark's relationship an iconic pairing on par with Meredith Grey and Derek Shepard. But they're not on par with Denny Duquette and Izzie Stevens, just FYI — they are forever the One True Pairing.

Shonda Rhimes wrote both characters off of the show permanently after Chyler decided she wanted to leave Grey's Anatomy because Lexie and Mark's relationship was "meant to be," just like the characters said in their passing breath. They were so meant to be that fans have conveniently overlooked a lot of inconsistencies, factual anomalies, and things that just make no sense about the couple. Some of the pairing's idiosyncrasies are so obvious that it is easy to forget they were ever a problem, like their massive age difference or the couple perishing in a statistically improbable plane crash, but others have been hiding in plain sight like their similarities to MerDer and their lack of interactions during the first two seasons. Through a massive amount of online research, I've compiled a list of 20 Things That Make No Sense About Mark And Lexie’s Relationship.

The Age Difference

Grey's Anatomy isn't always great with timeline continuity. Just look at the confusion around the newest Grey sibling, Maggie, and her supposed age. The gap between Mark and Lexie's ages could be even larger than the sixteen years that was established during season six, but the current canon is that Lexie was born in 1984 and Mark was born in 1968. A twenty-six-year-old dating a man in his early forties is way weirder than the kitschy jokes that the show would occasionally make about Mark dating "Little Grey," but as the seasons went on, the size of the age gap got buried under more dramatic issues like plane crashes, infidelity, and surprise pregnancies.

Shonda Only Ended Mark So His Love For Lexie “Could Remain True”

Mark Sloan death

Mark Sloan did not have to perish. One more time, loudly, for the people in the back: Mark Sloan did not have to perish! Shonda Rhimes eliminated the character because of Chyler's desire to leave, not actor Eric Dane's wishes. Shonda didn't want to keep Mark around without Lexie because she felt him passing was the only way to ensure that their love remained true. She didn't have these qualms with Alex when Izzie perished, with Izzie when Denny passed, or even with Meredith when Derek passed. All of those characters continued to date and move on with their lives on the show, but that didn't make their love any less true. There were still places to take Mark's character development, especially when faced with a personal tragedy of this scale.

Mark’s Children Harmed Their Relationship Twice

Mark and Lexie's first big breakup came when Sloan Riley came into the picture. Sloan was Mark's pregnant eighteen-year-old daughter who he learned about in season six of Grey's. Lexie didn't want to be a grandmother at the age of twenty-six, but Mark chose Sloan and the baby over Lexie, which was the right thing to do even if Sloan did eventually give up the baby and disappear. This issue would come up again when Mark fathered Callie's child in season seven, also by accident, and Lexie again couldn't deal with the pressure of Mark having a baby to raise and left him. Usually Grey's waits more than one season to recycle their plot lines.

He Accidentally Fathered Callie's Child?

Speaking of Callie, it makes no sense that Mark would have accidentally ended up fathering Callie's child in the first place. Mark was a notorious womanizer. That aspect of his personality, more than his surgical skills, his love for Lexie, or his dedication to family, is what defined the character on the show and for many fans. Having a child accidentally eighteen years earlier is plausible because twenty-four-year-old humans are still developing their frontal lobe, but for a forty-two-year-old man to accidentally end up with a coworker, there had to be an act of divine intervention.

They Barely Interacted For Two Years

Lexie was introduced late in season three a little after Mark became a full-time employee at Seattle Grace Hospital. Mark and Lexie went through all of season three and four barely interacting despite Mark's constant womanizing. Mark was involved with nearly every nurse at the hospital, in addition to other doctors, but he never made an impact on Lexie until season five. The only reason they even interacted was because Lexie was trying to protect George O'Malley from Mark's aggression. Then, suddenly, Mark found Lexie attractive enough for Derek to ban him from courting her, even though she'd been interacting with every significant figure in his life for at least a year at that point.

Mark Risked His Relationship With Derek

Mark came back for Addison Montgomery-Shepard, but he stayed to repair his relationship with Derek, a man who he considers his family (whom he had become estranged from after Mark spent time with Derek's then-wife, Addison). Repeatedly. After finally regaining Derek's trust and friendship, Derek asks Mark not to become involved with Lexie because she's is Meredith's little sister. Mark worked so hard to convince Derek that their friendship was worth saving, but he risked their relationship to pursue a romantic relationship with Lexie. Even before he realized they had a deep connection, he gave into Lexie's proposition even though, as a forty-something-year-old surgeon, he should reasonably have the self-control to not risk the most important relationship in his life for a possible one-time thing.

Lexie Pursued Her Boss

Lexie breaks up with Mark in Grey's Anatomy

There are two types of Grey's Anatomy fans: those who live for moments like Lexie showing up at Mark's door and asking him to teach her, and those who find moments like that one extremely corny and cringe-worthy. Realistically, all fans are a little of both, but Lexie speaking to her boss like that is definitely out of the realm of normal. Imagine going up to your boss and freely speaking in such a way. Or, if you are a boss, imagine one of your employees showing up at your house after one day of conversation and then showing deep romantic interest in you. It's a pretty upsetting visual, even if you and your boss/employee are as star-worthy as Grey's Anatomy characters. It's a weird way to start a weird relationship.

It Took A Plane Crash For Mark To Admit His Feelings

The final time Lexie and Mark break-up, Lexie asks Mark to stop pursuing her so that she can finally move on because she will always love him. Mark agrees because it's what Lexie wants and tries to move on. When Lexie finally tells Mark that she wants to be with him and loves him, he just thanks her. It takes a literal life-or-demise situation for Mark to get the courage to tell her that he also thinks they are "meant to be," days after Lexie admitted her feelings. Mark spent days trying to avoid his true feelings, and there's no way to know if he would have ever admitted them to Lexie without the intervention of a crazy accident.

And They Both Perished Because Of That Plane Crash

Speaking of that plane crash, the odds of both Lexie and Mark perishing in a plane crash are slim to none. International Business Times reports that there is a one in eleven million chance that someone will perish in a plane crash. Compare that to passing in a car crash (one in five thousand), passing just from falling down (one in thirty-six thousand), or perishing from a shark bite (one in three million), and the complete ridiculousness of a couple passing in a plane crash is really put into perspective. And it's not only because the odds of a crash are so low — in real life, but 95.7 percent of passengers in a plane crash will also survive.

Mark Mentored Jackson

Jackson's relationship with Lexie began because Mark recruited his protege to watch Lexie and find out why she had been feeling upset. Jackson uses the opportunity to convince Lexie that she should be with him, and although Mark is initially furious, he eventually gives the relationship his blessing. Mark even continues to mentor Jackson in plastic surgery. This could be considered character development, showing that Mark has matured and is able to prioritize other people's happiness over his own, but it's hard to imagine anyone being such good friends with the person who, effectively, stole his girlfriend. It's also weird to think about Jackson being so cool with spending his time learning from the man his girlfriend clearly still loves.

They Managed To Keep Their Relationship Hidden

Lexie and Mark lying in a bed together in Grey's Anatomy

Grey's Anatomy characters are reliably bad at keeping secrets for long, but Mark and Lexie were able to keep their relationship under wraps until Mark told Derek, which resulted in a fist fight in the middle of the hospital. Before then, Lexie and Mark were in an on-call room where people could hear the sounds of their voices, and still, no one figured out they were together. It's so unrealistic that no one would have seen them entering or leaving the room, or that the interns could identify Mark's voice but not the voice of another intern that they work with every day. Between that and the pair teasing each other in the middle of the hospital, the doctors at Seattle Grace might want to get their eyes checked because they missed something obvious.

Mark Was Constantly Proposing But Doesn’t Respond When Lexie Announces Her Love To Him

Mark, surprisingly, was always the one to keep moving his relationship with Lexie forward. Well, trying to, anyway. He pseduo-proposed when the pair talked about moving in together early in their relationship, then again while she's dating Alex. We already know it made no sense that Mark didn't get up the nerve to tell Lexie his feelings for her until the plane crash, but Mark's radio silence during Lexie's final admission of love makes even less sense when put into the context of his multiple proposals. Mark made it very clear that he was all-in from their first night together and intended to make Lexie his wife, so his sudden lack of decisiveness was out of character

She Helped George Study Instead Of Doing An Awesome Surgery With Mark

george and lexie

Mark and Lexie barely interacted before season five, but that doesn't mean they weren't aware of each others' existence. It actually would have made more sense for Lexie and Mark to have not known about each other than actual storylines like Lexie giving up a rare surgery with Mark to help George study for his intern exam re-take. Lexie knew Mark and was completely uninterested in him during her infatuation with George. George O'Malley was a hero, but anyone with eyes would be attracted to Mark Sloan. Lexie was so in love with someone who wasn't Mark that she gave up a chance to work on a once-in-a-lifetime surgery, which would be out of the ordinary for any intern, even if they weren't the resident surgeon's soulmate.

Alex Abandons Lexie After She And Mark Save His Life

It's weird that Lexie and Alex Karev ever dated in the first place. Meredith knew how damaged Alex was after Izzie left him and how self-destructive he could be, so letting the pair see each other without intervening was unlike her. Later, when Alex is injured in Seattle Grace's gun scare in season six, he only stays alive because Mark and Lexie work together to save him, but that doesn't stop Alex from abandoning her during her time of need when Lexie develops PTSD because of the event. Alex can be cruel, but after his character development throughout the series, that was weird for him, too. Mark and Lexie's relationship had its flaws, but it was strange how other characters would act so unlike themselves when the couple was involved.

Lexie’s Vision Of Her Future With Mark Included Kids

Chyler Leigh as Dr Lexie Grey in Grey's Anatomy

During Lexie and Mark's final conversation while Lexie was succumbing to her injuries, Mark tells Lexie the story of their future together. She passes away picturing their life together, which came with marriage, a beautiful home, and a family. Strangely, the reason Mark and Lexie kept breaking it off was that Lexie thought she was too young for children.  By this time, Lexie was roughly twenty-eight years old, so if children were a part of her perfect future, they would be coming in the near future. Mark was clearly willing to wait, seeing as their on-and-off relationship lasted for three to four years, so there was no reason that had to be a dealbreaker in their relationship after Sloan and her child were out of the picture.

They Spent More Time Apart Than They Did As A Couple

Mark and Lexie are "meant to be." That's the official, Shonda-approved stance. They're soulmates. Funnily enough, the couple made their huge impact on the fans and the writers despite being apart for longer than they were together. Similarly to Izzie and Denny, who appeared as a ghost for more episodes than he was in as a living, breathing person, Mark and Lexie spent most of their time on the show broken-up, never lasting a whole season together. For a couple with such a mythically true love, they were never able to work through their issues and make their relationship last. Even if Lexie and Mark had survived that plane crash, they probably would have broken up again by the middle of season nine.

They Totally Echoed Merder, But With A Different Outcome

Derek and Meredith Meet on Grey's Anatomy

Reddit user bluesapphire33 pointed out that Mark and Lexie are eerily similar to Meredith and Derek. Like Meredith and Derek, Lexie began a relationship with an attending while she was an intern, then proceeded to avoid his attempts to make the relationship more serious as time went on. Lexie and Meredith share obvious daddy issues (and, you know, a father), and Mark and Derek have similar taste in women, so the parallels wouldn't be that surprising if they didn't come with vastly different outcomes. Lexie was the bright and shiny of the Grey sisters, but somehow Meredith was able to set aside her issues for Derek, while Lexie was never able to do so for Mark.

One Conversation Turned Mark Into A Monogamist

Another issue pointed out by a Reddit user, audreymarilynvivien questioned the couple's dubious origin story. After Mark and Lexie's first night together, Mark's personality took a complete turn. He went from being such a romanticizer that the nurses formed a union against him to a committed, family-focused man. This Redditor didn't think it made sense that one conversation with Lexie was so mind-blowingly unique that Mark changed everything about his romantic life for her. We're never shown the conversation, and it's barely mentioned after their relationship begins in earnest. It seems like the writers may have just been looking to justify the storyline they had planned for the characters without needing to lay a proper foundation.

Jo Has Been In More Episodes Than Both Mark and Lexie

An image of Camilla Luddington as Jo Wilson on Grey's Anatomy

For one of the most-remembered couples in Grey's Anatomy, Mark and Lexie weren't actually series regulars for that much of the show's history. Some viewers split the show into three eras: the early years, the middle years, and the later years. Not the most original wording, but it works. Mark and Lexie's relationship was a hallmark of the series' middle years, which ended with season nine, but some of the later years' characters have now outlasted them. Jo, in particular, has been in more episodes than both Mark and Lexie, as has Nurse Bokhee, Jackson, and April, and Maggie and Amelia have both been in more episodes than Lexie. The later years have taken over.