My Favorite Half-Night Stand

My Favorite Half-Night Stand (2018) is a contemporary romance novel by Christina Lauren, the pen name of bestselling writing team Christina Hobbs and Lauren Billings. Known for popular works like The Unhoneymooners and The Soulmate Equation, the duo has established a significant presence in the romance genre. The novel follows a group of close-knit academic friends who make a pact to find dates for a university gala using an online dating app. The situation becomes complicated when Millie creates a secret online persona with whom Reid unwittingly begins an emotional correspondence. The novel explores themes of The Necessity of Vulnerability for Intimacy, Performing Identity in the Digital Age of Dating, and The Dangers of Moving From Friendship to Romance.

This guide refers to the 2018 Gallery Books trade paperback edition.

Content Warning: The source material and this guide feature depictions of illness, death, sexual content, and cursing.

Plot Summary

Millie Morris, a criminology professor at UC Santa Barbara, spends most of her time with her four best friends: Reid Campbell, an associate professor in neuroscience; Ed D’Onofrio, a postdoc researcher in Reid’s lab; and fellow professors Chris Hill in chemistry and Alex Ramirez in biochemistry. At a party celebrating Reid’s tenure, Chris announces that Barack Obama will be the keynote speaker at the university’s upcoming black-tie Deans’ Banquet. He proposes that the five of them, all single, make a pact to find dates for the event using an online dating service.

Later that night, a tipsy Millie experiences a sudden, intense sexual attraction to Reid. He drives her home, and after a conversation about their lackluster dating lives, she impulsively invites him inside. Acknowledging their mutual attraction, they kiss and decide to have sex, establishing two ground rules: It is a one-time event, and they will not tell their friends. Reid leaves in the middle of the night, creating what their friend Ed later defines as a “half-night stand”: hooking up and leaving right after the sex is over. 

The next morning, Reid feels anxious about potential awkwardness, but Millie visits his office with a “morning-after cupcake” to confirm that their friendship is intact. They agree to proceed with the plan to find other dates for the banquet.

The group decides to join a premium dating site called In Real Life (IRL) because it offers more privacy for women. Millie critiques the men’s poorly written profiles and agrees to rewrite them. Her own profile, however, is short and vague. It garners only inappropriate messages and an unwelcome match with her ex-boyfriend, Dustin. 

During a group lunch, Millie has an awkward encounter with her sister’s friend, Avery Henderson, who alludes to Millie’s father’s health problems. Millie quickly deflects Avery’s concern, a manifestation of her long-standing emotional avoidance, which is rooted in her mother’s death. Frustrated with her dating results, Millie creates a second, secret profile under her middle name, “Catherine M.” This new persona features an artsy, obscured photo, and it allows her to express an emotional vulnerability she avoids in real life.

Reid matches with two women on IRL: the conventionally beautiful Daisy D. and the mysterious Catherine M. He is more visually drawn to Daisy, but he also matches with Catherine (unaware of her true identity) after she sends him a witty introductory message, and the app shows them as a 98% compatibility match. 

At lunch, Millie becomes uncharacteristically defensive, arguing for personality over looks, when the guys dismiss Catherine because of her non-revealing photo. Driven by jealousy, Millie helps Reid write replies to both women, deliberately making his message to Catherine more engaging. This begins a deep, anonymous correspondence in which Millie, as Catherine, shares personal stories and vulnerabilities she has never shared with Reid in person.

The complications escalate when Reid’s date with Daisy proves to be a disaster due to a complete lack of chemistry. He goes directly to Millie’s house afterward, and, driven by relief that his date went poorly, she initiates sex with him for a second time. When he tries to discuss their relationship, however, she becomes emotionally distant, casually planning to leave for her office immediately after they have sex. Believing that their connection is purely physical to her, he leaves feeling hurt. 

The friend group travels to Reid’s parents’ vineyard for his birthday weekend. During the trip, Ed overhears Reid and Millie having sex for a third time, and he discovers her “Catherine” secret after seeing her on the app. Reid, meanwhile, becomes increasingly invested in his conversations with Catherine, telling Millie how easy Catherine is to talk to, unaware he is speaking to the same person. His confusion about his feelings for Millie leads him to send Catherine a long message asking to meet in person to see if their connection is real.

Panicked, Millie goes to speak to Ed about it, and when she finds Alex there as well, she asks them both for advice. They advise her that the only way out is for “Catherine” to disappear, and they help her compose a message to Reid. As Catherine, Millie tells Reid that she has reconnected with someone from her past and is ending their correspondence. 

Reid is heartbroken by Catherine’s rejection, and he is happy for the distraction when Millie calls and asks to talk. When he arrives at her house for their conversation, he embraces her and notices a distinctive crescent-shaped scar on her shoulder, which he recognizes from Catherine’s profile picture. This detail, combined with her unique “tit” for “it” typo and their shared personal stories, makes him realize Millie is Catherine. Over the course of their conversation, he gives her multiple opportunities to confess, but she continues the deception by omission. 

Feeling profoundly betrayed, Reid tells her he needs time to think and leaves. He later confronts the guys and learns that Ed and Alex knew about the deception, which deepens his sense of betrayal, and he cuts off contact with everyone.

The next day, Millie goes to Reid’s house and confesses everything. Reid reveals he already knew and ends things with her, explaining that he cannot start a relationship based on a lie. For three weeks, the friend group is fractured, with Reid and Millie avoiding each other. 

Heartbroken, Millie updates her original IRL profile under her real name and begins sending Reid daily messages, opening up about her past, her fears, her family, and her love for him. She also starts therapy. Reid reads every message but does not reply, although he eventually reconciles with Ed and Alex. Finally, Millie sends a message revealing that her father has Parkinson’s disease and that she is going home to Seattle for the summer to help care for him after surgery. 

Upon reading this, Reid immediately goes to Millie’s house. They have a tearful reunion, where she is finally able to be emotionally vulnerable with him in person. He forgives her, and they commit to being in a real relationship.

In the epilogue, set later that summer, Millie is in Seattle caring for her father, who is recovering well. Her relationships with both her father and her sister, Elly, have healed. Reid is with her, supporting her, and their relationship is happy and strong. Alex, Chris, and Ed are visiting, showing that the friend group is reunited. The friends play a game of Monopoly as Millie reflects on her newfound emotional honesty and the happy, stable family she has found with Reid and their friends.