Lea and Shaun started out as neighbours, became friends, and then eventually acted on their mutual attraction and became romantically involved. Here is their story.
Neighbours to Friends
Shaun first met Lea, his direct next door neighbour at the time, when she knocked on his door to borrow batteries for her PS3 controller. They became friends, and even though there was flirting and mutual attraction, their relationship did not evolve into anything romantic until the season 3 finale.
During a time of personal crisis for Shaun, Lea took him on a road trip where Shaun had a lot of ‘firsts’ — first time driving a car, first time drinking Tequila, first time singing karaoke, first time kissing a woman (1×11 Islands Part 1). The road trip ended with Lea deciding to quit her job in San Jose to move back to Hershey and live her dream of rebuilding old cars together with her brother Donnie.
Shaun was very upset by this turn of events and at first decided he would move to Pennsylvania with her and finish his residency there, but eventually was persuaded (not lastly by Dr. Glassman) to stay in San Jose. Lea left for Hershey in 1×12 Islands Part 2, leaving Shaun her baseball signed by Hunter Pence to remember her by.
It was in the season 2 premiere (2×01 Hello — written by Freddie Highmore himself) that Lea came back to San Jose from Hershey, greeting Shaun in front of his apartment door very out of the blue. Shaun let her stay on an camping mat in his apartment for a while until Lea found a new place to live.
Their time living together in Shaun’s studio apartment was strained — Shaun found it unsettling that Lea was unexpectedly back, and infered her previous farewell to mean that she would leave again, which he knew would upset him. He avoided her as best as he could and in the meantime sought advice from friends and colleagues how to handle the situation.
Not wishing for Lea to leave again, as part of a grand gesture from Shaun, he rented out an apartment for the two of them to share that Lea fell in love with but that was too big for her to live in on her own. Lea at first refused on the grounds of not being comfortable to be sending explicit signals that she was interested romantically in Shaun.
Lea eventually agreed for them to move in together, though insisting that she would like her relationship with Shaun to stay purely platonic, although the underlying chemistry between them was always there. Shaun and Lea shared the apartment as roomies throughout the second half of season 2 and the first half of season 3. During this time, Lea dated at least once, a guy named Jake that seemed to be more of a casual hook-up than an actual boyfriend. (In 3×15 Unsaid, Shaun mentioned that Lea definitely used protection every time one of her boyfriends would come over, so most likely he’s seen her hook up with several men while she was living with Shaun.)
Veering Off the Shaun/Lea Course
At the very end of season 2, Shaun started dating Carly Lever, Head of Pathology at St. Bonaventure Hosptial. (Interestingly, Lea seemed to be somewhat taken aback and disappointed when Shaun asked Carly out on a date instead of her.) Carly was Shaun’s first girlfriend and relationship (Lea having been Shaun’s first kiss); she was very understanding of his autism and the challenges it presented.
One of the biggest hurdles Shaun and Carly had to overcome was Shaun’s reticence about Carly touching him, and it took them a long time to work out how to get around that, and eventually lie in bed together and have sex. Carly taught Shaun a great deal about what it meant to be in a romantic relationship, although they had their rough patches.
Platonic Friends or Not?
Even though Shaun was dating Carly, Lea remained Shaun’s best friend and confidant, often giving him advice on how to handle tricky situations relating to his love life. The chemistry between Lea and Shaun stayed strong, to the point where Lea kept flirting with Shaun, perhaps also subtly or subconsciously trying to exert dominance over Carly. However, Shaun was mostly oblivious to these efforts as he focused his full commitment on his romantic relationship with Carly.
During Shaun’s dating journey with Carly, Carly’s jealousy of Lea became a bit of an issue, and she presented an ultimatum to Shaun that either Lea had to move out of their shared apartment, or Carly would end her relationship with Shaun (3×11 Fractured). Lea acquiesced and moved out shortly thereafter (3×12 Mutations).
In episode 3×15 Unsaid, Carly and Shaun happened upon Lea and her unnamed boyfriend (or date?) in a bar, and the four of them ended up singing karaoke together. There was definitely still a spark between Shaun and Lea, and Carly saw it too, which prompted her to end her relationship with Shaun, encouraging him to tell Lea that he loved her more than Carly.
One night, Shaun gathered the courage and invited Lea over for dinner, where he confessed to her that he loved her (3×16 Autopsy, directed by Freddie Highmore). Perhaps somewhat surprisingly, Lea told Shaun that she wasn’t ready to be in a relationship with Shaun because it would be too challenging. Their friendship became very strained afterwards, with Shaun trying to win her over, and Lea continuing to reject his efforts.
The tides turned in episodes 3×19 Hurt and 3×20 I Love You, where both got trapped in a collapsed building after an earthquake and Lea listened to Shaun talking about his love for her over the radio as he had to wait for a rescue team to retrieve him and a trapped patient. When both Lea and Shaun were finally freed, she changed her mind and told him that she loved him, too.
Lea and Shaun became a couple thereafter, Lea moving back in with him into the apartment they previouly shared as roommates.
Lea became unexpectedly pregnant in episode 4×11 We’re All Crazy Sometimes. After some deliberation and an initial decision to abort the pregnancy, they redecided to keep the baby, which was revealed to be a girl.
Lea and Shaun tragically lost the baby in 4×16 Dr. Ted. There were complications with the pregnancy (see my Patient Case Review writeup for more details), and the baby couldn’t survive. Shaun and Lea made the difficult decision to abort the pregnancy. Both struggled with the loss of their child in different ways, but supported each other through this difficult time.
During a medical relief mission to Guatemala (season 4 finale), Lea proposed to Shaun to marry her, and Shaun said yes. We can look forward to seeing what happens with their wedding in season 5.
Andreas_from_Germany has written up an excellent post on Reddit about Lea and Shaun’s relationship and how the writers planted seeds and used certain recurring elements to tell that story. It’s a great read if you’re interested in delving further into the topic.