NOT "Just Friends": Rebuilding Trust and Recovering Your Sanity after Infidelity by Shirley P. Glass Summary

1. Emotional affairs often begin as innocent friendships that cross boundaries.
2. Glass introduces the Walls and Windows concept for understanding intimacy.
3. The Prevention Myth claims love alone cannot safeguard against infidelity.
4. Wait three months before deciding to end your relationship after betrayal.
5. Affairs frequently start when partners confide in friends over spouses.
6. Not Just Friends outlines three recovery stages after discovering infidelity.
7. The Fishbowl Technique allows betrayed partners to ask questions safely.
8. Workplace friendships become affairs when emotional boundaries shift dangerously.
9. Glass emphasizes both partners must work actively to rebuild broken trust.
10. Setting clear friendship boundaries prevents emotional affairs from developing naturally.
11. Shirley Glass explains why being a loving partner isn't enough.
12. Recovery from infidelity requires understanding vulnerabilities within your relationship.

About the Author

Shirley P. Glass (1936–2003) was the author of Not "Just Friends": Protect Your Relationship from Infidelity and Heal the Trauma of Betrayal and a pioneering clinical psychologist specializing in marital infidelity and relationship recovery. Dubbed "the godmother of infidelity research" by The New York Times, Dr. Glass conducted groundbreaking research on extramarital affairs beginning in 1975 and treated hundreds of couples in her Baltimore-area private practice over 25 years. She held a PhD in psychology from Catholic University and was a licensed psychologist with a diplomate in family psychology and a fellow of the American Psychological Association.

Dr. Glass revolutionized understanding of modern infidelity by identifying the workplace as the primary breeding ground for affairs and introducing the influential "walls and windows" framework for relationship boundaries. Her insights on emotional affairs challenged the assumption that only unhappy marriages are vulnerable to betrayal.

She appeared on Oprah, Good Morning America, Today, and NPR's Fresh Air, and was featured in major publications including USA Today, Psychology Today, and Newsweek. Dr. Glass was the mother of Ira Glass, host of This American Life. She completed her book shortly before passing away from breast cancer in 2003, leaving a lasting legacy in couples therapy worldwide.

FAQs About This Book

What is Not "Just Friends" by Shirley P. Glass about?

Not "Just Friends" by Shirley P. Glass is a comprehensive guide to understanding and healing from infidelity, particularly emotional affairs that begin as innocent friendships. The book explores how close bonds can cross boundaries even in strong relationships, detailing the stages of emotional affairs, warning signs, and the trauma of betrayal. Glass provides step-by-step guidance for both betrayed and unfaithful partners through the process of rebuilding trust, recovering sanity, and restoring intimacy after an affair.

Who should read Not "Just Friends" by Shirley P. Glass?

Not "Just Friends" is essential reading for couples dealing with infidelity, therapists working with betrayed partners, and anyone seeking to affair-proof their relationship. The book addresses both the betrayed spouse and the unfaithful partner, making it valuable for couples working through recovery together. Even individuals in seemingly strong marriages should read this book, as Shirley P. Glass emphasizes that good relationships aren't immune to affairs and that preventive awareness is crucial for long-term relationship health.

Is Not "Just Friends" worth reading in 2025?

Not "Just Friends" remains highly valuable despite being published in 2002, with therapists and couples consistently praising its practical insights and research-backed approach. The book's core principles about emotional boundaries, trust rebuilding, and affair prevention are timeless, though some readers note the workplace affair focus feels dated in today's remote work environment. Many reviewers recommend reading it before marriage or during serious dating as a preventive measure, with several stating they wish they had discovered Shirley P. Glass's insights earlier.

Who is Shirley P. Glass and what are her credentials?

Shirley P. Glass, PhD, was a renowned clinical psychologist and marriage therapist who specialized in infidelity for over 25 years. She conducted extensive research and case studies on extramarital affairs, becoming a leading authority on emotional infidelity and relationship betrayal. Glass was also the mother of Ira Glass, host of NPR's This American Life, who provided the book's opening quote: "You know you're in trouble when the word 'just' appears before the word 'friends.'"

What is emotional infidelity according to Not "Just Friends"?

According to Shirley P. Glass in Not "Just Friends," emotional infidelity is a close emotional relationship with someone outside your primary partnership that threatens the romantic bond, even without physical intimacy. Glass defines it through deep emotional connections, shared secrets, and intimacy that should be reserved for one's partner. The book emphasizes that emotional affairs can feel equally or more damaging than physical adultery because they involve giving away emotional energy, vulnerability, and intimate thoughts that create distance from one's committed partner.

What are the warning signs of an emotional affair in Not "Just Friends"?

Not "Just Friends" identifies key warning signs including increased secrecy about communications, emotional distance from your partner, and spending excessive time texting or talking with someone outside the relationship. Shirley P. Glass highlights behaviors like sharing intimate thoughts with a friend before your partner, looking forward to interactions more than time with your spouse, and becoming defensive when questioned about the friendship. The book emphasizes that when you start hiding interactions or downplaying their significance by saying they're "just friends," boundaries have likely been crossed.

How does Not "Just Friends" help rebuild trust after infidelity?

Not "Just Friends" provides a step-by-step roadmap for rebuilding trust through transparency, accountability, and open communication about intentions. Shirley P. Glass recommends the unfaithful partner voluntarily share details about their whereabouts and interactions while minimizing contact with the affair partner. The book guides couples through establishing new boundaries, addressing the betrayed partner's hypervigilance, and creating strategies for demonstrating dependability over time. Glass emphasizes that healing requires the betrayed partner to fully process their emotions with support from loved ones or therapists.

What boundaries does Shirley P. Glass recommend in Not "Just Friends" to prevent affairs?

Shirley P. Glass emphasizes establishing clear boundaries in opposite-sex friendships and workplace relationships through transparency and open communication with your partner. Not "Just Friends" recommends sharing details about friendships, avoiding one-on-one situations that could lead to intimacy, and recognizing when emotional needs are being met outside the primary relationship. The book advocates for "windowed walls" rather than walls between partners—being transparent about outside relationships while maintaining appropriate walls with others. Glass stresses that healthy relationships require active maintenance and clear agreements about what constitutes appropriate friendship behavior.

What are the main criticisms of Not "Just Friends"?

Critics of Not "Just Friends" note that the research feels dated, particularly its heavy focus on workplace affairs and gendered assumptions about men and women's affair patterns. Some readers find the Mars-Venus dichotomy limiting, arguing it overlooks individual experiences in favor of stereotypical gender roles. A few reviewers mention occasional religious undertones that may not resonate with all readers. Additionally, some find the content repetitive and occasionally dry, though most agree the practical insights outweigh these concerns for those dealing with infidelity.

How does Not "Just Friends" compare to The State of Affairs by Esther Perel?

Not "Just Friends" by Shirley P. Glass takes a more clinical, research-based approach focused on prevention and rebuilding trust, while Esther Perel's The State of Affairs explores the broader cultural and psychological meanings of infidelity. Glass provides structured steps for recovery with emphasis on transparency and accountability, whereas Perel examines why people cheat with more nuance about desire and identity. Many readers note that Perel clearly built upon Glass's foundational work, with The State of Affairs offering a more contemporary, less gendered perspective that some find richer for understanding individual motivations beyond traditional relationship frameworks.

What does Shirley P. Glass say about preventing affairs in good marriages?

Not "Just Friends" directly challenges the myth that loving partners and good marriages are immune to affairs. Shirley P. Glass emphasizes that no relationship is low-maintenance or invincible to infidelity, and that people in seemingly strong marriages have affairs too. The book highlights that prevention requires active commitment—one man shared his approach of being "committed to my wife on good days, committed to my marriage on okay days, and committed to my commitment on bad days." Glass argues that couples who believe their marriage doesn't need improvement are actually at the highest risk for affairs.

Why is Not "Just Friends" still relevant for relationships in 2025?

Not "Just Friends" remains relevant in 2025 because emotional infidelity has intensified with social media, texting, and digital communication making constant connection easier than ever. While Shirley P. Glass's 2002 focus on workplace affairs may feel dated in the remote work era, her core insights about emotional boundaries and how friendships cross into betrayal apply even more urgently to today's always-connected culture. The principles of transparency, recognizing warning signs, and rebuilding trust are timeless, making the book's framework essential for navigating modern relationship challenges where emotional affairs can develop through DMs, texts, and online interactions.