Relationships
Why Lust Can Fade in Long-Term Relationships
Can too much closeness kill sexual desire for a partner?
Updated July 28, 2025 Reviewed by Gary Drevitch
Key points
- People tend to crave sex when they need to increase closeness, not when intimacy levels are high and stable.
- The need for security and closeness can conflict with the novelty and separateness that fuel passion.
- Maintain your own life and introduce novelty to see your partner in a new light.
We are all familiar with this script: Your partner is your best friend. You feel incredibly comfortable with each other—so comfortable that you’re doing things in front of each other you never imagined you’d do when you first started dating: leaving dirty socks scattered around, wearing torn T-shirts, shaving your legs while they’re in the room, and putting on your favorite cucumber face mask during dinner.
You tell each other all your secrets and speak in one voice, completing each other’s sentences. You trust them, and you love them. But when night comes, you prefer to cuddle rather than have the wild sex you used to have years ago. You ask yourself: “What happened to our lust? Once, when we were almost strangers, we couldn’t keep our hands off each other.” Now, when your partner walks naked in front of the TV, you politely ask them to move so you can watch it without interruption.
Why Does Intimacy Affect Sexual Desire?
There are many reasons for having sex1. One of the most prominent is the desire to feel closer to a partner2. So, you crave sex when you feel the need to increase closeness and intimacy—not when you feel that your partner is already a part of you (or when you take your partner for granted).
When intimacy levels are high and stable, as is often typical of long-term relationships, the need for further intimacy is low—and so is the corresponding urge for sex with that partner. For example, if you reach the point where you feel you know everything there is to know about your partner, while having no opportunities to share new experiences or otherwise increase intimacy, your sexual desire for them can drop precipitously—even if the intimacy between you remains high.
However, the act of increasing intimacy—by learning new things about your partner or discovering that your partner cares for you in a new way—is sexually exciting. It makes you see your partner in a new light. As relationship experts have long noted, sexual desire thrives on change and mystery, not stagnancy3,4.
Research indeed shows that high but stable intimacy is not associated with higher desire. Rather, it is the increase in intimacy that fosters desire5,6.
The Paradox at the Heart of Romantic Relationships
One paradox of romantic relationships is that as intimacy and commitment grow, desire and passion often decline7. This paradox may arise from the contradiction between the security that a familiar relationship provides and the sense of novelty, uncertainty, and separateness that sparks desire4.
Maintaining a sense of individuality or distinctiveness alongside closeness can enhance sexual desire8. The key factor in whether intimacy fuels or inhibits desire lies not in its existence but in its contextual meaning9(read more here). When partners maintain their distinctiveness, it can kindle the desire for intimacy and physical closeness. Conversely, when partners lack sufficient differentiation, the drive for sex decreases because there’s less motivation to seek what is already abundantly available2.
Rekindling Desire Through Novelty and Distinctiveness
Novelty is crucial to sparking sexual desire—and that doesn’t have to mean sex toys and roleplay. Foreplay, in this sense, starts long before you get to the bedroom. It means keeping things fresh: talking about new topics with each other, doing new and exciting things together, and learning new skills as a team.
Try to observe your partner in different circumstances and in the various roles they play in their life that are not necessarily familiar to you. You may discover that your partner isn’t the predictable person you’ve already learned everything about after all, and that there’s still more you can learn about them—and get excited about.
Still, it’s also vital to maintain distinctiveness and your own life. It’s important to have your own friends and your own hobbies so that you don’t feel fully enmeshed. Often this separation helps boost desire, as you are less likely to desire what you feel you already have. After all, the desire to get closer to your partner is sexy. Perceiving them as a piece of comfortable furniture you already own? Not so much. Overall, the goal isn’t to be less intimate but to create a space between you—a space that can be filled with curiosity, longing, and renewed desire.
Facebook image: PeopleImages.com - Yuri A/Shutterstock
References
1. Meston, C. M., & Buss, D. M. (2007). Why humans have sex. Archives of sexual behavior, 36, 477-507.
2. Birnbaum, G. E. (2018). The fragile spell of desire: A functional perspective on changes in sexual desire across relationship development. Personality and Social Psychology Review, 22(2), 101-127.
3. Birnbaum, G. E., & Muise, A. (2025). The interplay between sexual desire and relationship functioning. Nature Reviews Psychology, 4(3), 193–206.
4. Perel, E. (2007). Mating in captivity: Sex, lies, and domestic bliss. Hodder.
5. Baumeister, R. F., & Bratslavsky, E. (1999). Passion, intimacy, and time: Passionate love as a function of change in intimacy. Personality and Social Psychology Review, 3(1), 49-67.
6. Rubin, H., & Campbell, L. (2012). Day-to-day changes in intimacy predict heightened relationship passion, sexual occurrence, and sexual satisfaction: A dyadic diary analysis. Social Psychological and Personality Science, 3(2), 224-231.
7. Ferreira, L. C., Narciso, I., & Novo, R. F. (2012). Intimacy, sexual desire, and differentiation in couplehood: A theoretical and methodological review. Journal of Sex & Marital Therapy, 38, 263-280.
8. Muise, A., & Goss, S. (2024). Does too much closeness dampen desire? On the balance of closeness and otherness for the maintenance of sexual desire in romantic relationships. Current Directions in Psychological Science, 33(1), 68-74.
9. Birnbaum, G. E., Reis, H. T., Mizrahi, M., Kanat-Maymon, Y., Sass, O., & Granovski-Milner, C. (2016). Intimately connected: The importance of partner responsiveness for experiencing sexual desire. Journal of Personality and Social Psychology, 111(4), 530-546.
