[This story contains spoilers fromThe Sex Lives of College Girlsseason 3, episode 2, Lila by Lila.]

The OG girl group in The Sex Lives of College Girls has officially lost a member.

Bela (Amrit Kaur), Kimberly (Pauline Chalamet) and Whitney (Alyah Chanelle Scott) said their goodbyes to Leighton (Rene Rapp) in the second episode of the Max shows third season, which aired Thursday. While fans always knew Rapp would be exiting the series this season, they just didnt know exactly when or why until now. The second episode sees Leighton make the difficult decision to transfer from Essex College to MIT. While her girlfriend, Alicia (Midori Francis), is also in Boston, Leighton is ultimately transferring because of MITs math program, which will help her with her future career in finance.

I dont wanna go, Rapp tells her friends at one point. I cant imagine not having you guys with me. It is terrifying. But I think this is what I have to do if I care about my future.

But before Leighton officially hits the road with her father, she spends one final night partying at Essex with her besties, which includes a pregame in their old college dorm suite.

Co-showrunner Justin Noble also previously spoke with The Hollywood Reporter about how they decided on Rapps farewell storyline: We kind of landed on this pretty quickly. I mean, when you start to think about ways that college students leave, youre pretty limited. Its not like Renes character was gonna go on a hike, and then Kimberlys like, You mean the rocky, dangerous hike near the cliff? And then, she falls off or something. Really, the only thing that could happen was that she would transfer to a different school.

But as we started talking about it, Mindy and I were chatting, were like, This is Leighton Murray were talking about. The only thing Leighton Murray does is win,' she continued. So theres no world where she would leave other than to take a massive step towards what would be her best, most powerful life moving forward.

News broke over the summer of 2023 that Rapp, who has gone on to launch a hit music career, would be leaving the series during its third season. At the time, THR reported that she would appear in a few episodes as a recurring guest star, not a series regular, to set up Leighton leaving Essex.

Leighton discovered her math aptitude in Sex Lives of College Girls first season, being told by a professor that she belongs in a more advanced class, feedback that she also turns into a way to get some verbal revenge against past friends who didnt want to room with her.

The seeds of Leightons departure were planted in the season three premiere where she walked into an empty classroom, save for Professor Tocchini (the same teacher who spotted her math skills freshman year), for a high-level math course only to be told it was canceled because she was the only student that passed the placement exam. Tocchini offers that she can take advanced courses at The University of Vermont, but the long bus ride quickly proves unbearable. After Leighton complains to Tocchini, he admits that Essex doesnt have the math curriculum she needs and offers to call a friend at MIT about a transfer.

In that same episode, Alicia revealed she was leaving Essex to work for the Boston mayor, making the Cambridge, Massachusetts-based MIT a geographically convenient option for Leighton.

In episode two, Leighton quickly learns she was accepted into MIT and could start as soon as next week. She goes through her concerns about leaving with her Essex-obsessed dad (Rob Huebel) and they decide its what she needs to do. But she still struggles to tell her best friends and suitemates since freshman year that shes leaving and they end up finding out from Jocelyn (Lauren Lolo Spencer) after she overhears Leighton returning her books because shes transferring.

The group confronts Leighton and she reveals its true: Shes leaving for MIT tomorrow morning. But shes terrified to leave her best friends and needs them to be supportive in order for her to have the courage to make the leap.

I came to Essex thinking I was going to date men and I would be in Kappa and I would have done those things. And I would have been miserable, she tells them. And then I met you three, and you gave me the strength to be myself.

When asked about her exit from the show in a February THR cover story, Rapp said the decision to leave was hard for so many reasons and recalled the difficult experience of coming to terms with her sexuality in her personal life as her character was doing so in the series.

On TikTok, [I watched] this scene in season one, where I come out to another character as a lesbian, and Im crying, sobbing, she told THR. And I hadnt seen that scene in years. It is so interesting that at the time I wasnt even aware that what I was experiencing in my own personal life was actually exactly what I was doing onscreen. I was in a relationship with a man, incredibly confused, unsure of myself, feeling so insecure in my acting. And I watched the scene the other day, and I was like, Wow, I feel so lucky to have that. Thats something I would show my kids. So when I watched it back, I was like, Yeah, thats hard to leave that.

Of that confusing time, she added, I would go home, and I would call my friends, and Id be like, I think Im a lesbian, but I really love my boyfriend. I would want to be with him, but I see him more as a friend. So not only was I doing that on the show, publicly, in a big way to so many people, and my family, who had no idea that I was gay, I was also going through it personally.

Rapp has said she was thrilled to audition for the role, previously saying in a 2023 appearance on Alex Coopers Call Her Daddy, before news of her Sex Lives departure broke, that shed never been asked to audition for a queer character.

Still, she recalled having a terrible time filming the first season.

I was just in a panic constantly, she said. And I wasnt [straight], butI was so freaked out by the idea of my sexuality not being finite or people laughing at me or me laughing at myself that I hated first year of filming.

And she said she was beating [herself] up so much.

I wanted so badly to do a good job, she said. I wanted to play the role in the way that if I saw it as a kid it would feel good to me. I also wanted to do a good job so bad that I was so nervous all the time. It was so much the first season.

The Sex Lives of College Girls drops new episodes on Thursdays at 9 p.m. ET/PT on Max.

Hilary Lewis contributed to this report.