Grey's Anatomy is as much a medical drama as it is a human drama. The ups and downs in the most perfect of relationships, shocking culminations, loss and death, are some of the running underlying themes in the series that has had many expected, obvious storylines, and some very unexpected, unanticipated romances.
Whether it was April's arc with Matthew, or Teddy cheating on Owen with Tom, the series has, over the course of almost two decades, given fans many couples who fans would have never even imagined would get together. And although most of them broke up, some, after the first shock, actually seemed to make sense.
Eli & Bailey
Miranda Bailey went through a phase when she was trying to find her way both personally and professionally. At that time, she started seeing the nurse Eli, and seemed to fancy him for a brief while.
Since fans were rooting for the adorable Ben Warren to be with Bailey since day one, her whirlwind thing with Eli seemed out of place and no-one really saw it coming. The relationship seemed to fizzle out anyway but while it lasted, fans did see Bailey's softer and emotionally driven personality.
Teddy & Tom
In season 15, Teddy was seen to get involved with Tom Koracick, the sarcastic but ultimately good-natured neurosurgeon. Teddy’s involvement with Tom made sense in the beginning since Owen was still with Amelia despite Teddy carrying his child. However, this relationship didn't last long as Owen and Teddy eventually admitted they were still in love with each other.
What did take fans by surprise was Teddy cheating on Owen with Tom on the very day that she was to get married to Owen. This was something fans never saw coming, and clearly, neither did Owen. Although the writers dropped the Tom-Teddy-Owen storyline, after the first shock, a lot of fans might actually have rooted for Teddy and Tom, and didn't want Teddy getting back with Owen.
Matthew & April
April Kepner was one of those characters who was widely disliked at first but then went on to make quite an impression on fans. During her time on the show, she was seen to have two major romances - one with Jackson and the other with Matthew, which fans did not see coming the second time around.
Not that April didn’t fit right in with Matthew too, in fact, the two made quite a lovely couple. But fans were way too invested in 'Japril' and were sort of devastated when April actually almost ended up with the introverted paramedic. Of course, after much drama, the 17th season hinted that April and Jackson were likely to reunite sometime in the future after the trauma surgeon revealed that she and Matthew were going to get a divorce.
Rose & Derek
MerDer fans were astounded when Derek decided to date Rose, the lovely nurse who was unlucky enough to become ‘McRebound.’ Rose seemed to genuinely like Derek, although there was no way fans were going to warm up to her. The romance, as expected, was short-lived and almost instantly forgotten.
However, the short span of time that Derek stayed away from Meredith apparently gave him a better perspective, so perhaps the romance meant something within the broader picture, after all.
Jackson & Maggie
At one point, the Grey’s universe did see some oddly matched pairings of characters, as it seemed that the writers were testing out a few ideas. And Jackson and Maggie were definitely one of those little experiments.
Fans never saw this pair coming together, and the pair did break up almost as fast as they declared themselves a couple. Although both Jackson and Maggie are much loved with the fans, sometimes, even the best of characters make unexpectedly terrible couples.
Maggie & DeLuca
Maggie Pierce might have found her one true love with Winston but there was a time when she had brief and unexpected romances. One of those was with Andrew DeLuca.
Maggie and DeLuca ended up sleeping one night after going out for a drink together. However, this relationship didn't last very long as DeLuca started to feel intimidated by Maggie's success. In the end, the two decided that they were just best-staying friends, which did suit them better in the long run.
Owen & Amelia
Owen Hunt is not a fan favorite but the fact remains that he has had a spate of unfortunate romantic entanglements. While his and Cristina Yang's relationship were, for the longest time, the series' second lead couple, many fans weren't on board with that particular relationship.
However, after they broke up, Owen got together with Amelia, an unlikely couple that seemed doomed from the beginning and that fans never expected or seemed to root for. The couple divorced soon after but not before some high drama.
Izzie & Denny
Izzie Stevens's romance with Denny Duquette became a significant part of Izzie's storyline throughout season 2. Denny, fans could hardly have forgotten, had a severe heart condition, and Izzie went to the extent of breaking almost every rule there was to get him a heart for transplant. She nearly got fired in the process but it was all in vain as Denny died all the same.
While Denny flirting with the lovely intern felt natural and fun, things took a sudden turn for the unexpected when what started out as casual became overly serious and the two actually fell in love with each other. So much so that Izzie risked her and everybody else's career for him. The fast-paced romance was something fans could not get on board with.
Callie & George
Another unexpected romance happened between Callie and George O'Malley at the very beginning of the series. Fans were taken aback when the couple actually became official and even got married on a whim in Las Vegas.
While fans adored both Callie and George, their pairing somehow made little sense and there was something about it that never sat quite right. Of course, their romance was never meant to be and to this day, Callie and George's romance remains an arc that simply didn't work.
Penny & Callie
The surgical resident, Penelope Blake, will forever be remembered by Grey's fans as being indirectly responsible for the shocking death of Derek Shepherd. Of course, it wasn't by any means Penny's fault as such, but she was still part of the team that mishandled Derek's case, which eventually led to his untimely demise.
To see Penny dating Callie Torres was probably one of the biggest shocks that fans got in terms of romantic storylines over the years. The arc became even more convoluted when Callie got into a long-drawn-out custody battle with Arizona over Sophia, after she chose to move to NYC with Penny, her new-found love.