It’s human nature not to trust someone who has lied to you. In the "Psychology Today" article "Why Lying Hurts So Much," by Susan Krauss Whitbourne, Ph.D., Whitbourne cites a study about lying and trust in which students rated a hypothetical boss who’d sent an email to employees about the company policy regarding working over the holidays. In one part of the study, the boss lied; in the other part of the study, the boss told the truth. Predictably, the students did not trust the boss who lied. In a romantic relationship, each person has invested trust in his partner. Unfortunately, when you are involved with a partner who lies, the relationship's foundation becomes shaky as it rests on lies, which spark pain and further distrust. “Liars make a deliberate choice to fabricate the truth and do not let others know that they are doing this,” says Paul Ekman, a psychologist and expert in the study of emotions, in Whitbourne's article.

Even if your partner's lying isn't built around a serious affair, but a series of small life issues, chances are those lies have caused you pain because of the deception involved. These types of small lies cause “a more gradual realization of what your life has become,” says Steven Sosny, Ph.D., in the "Psychology Today" article "Types of Intimate Betrayal." In a healthy relationship, trust and honesty result in greater emotional closeness between partners. Lying does not indicate a healthy relationship, because when one person lies, he is breaking the intimacy between himself and his partner. When lies abound, emotional intimacy cannot exist. And when emotional intimacy does not exist, physical intimacy is affected. In short, lying affects all areas of a relationship.

When trust disappears, vulnerability also disappears. In a "Psychology Today," "The Worst Kind Of Betrayal," Dr. Lissa Rankin discusses the book, “Daring Greatly: How The Courage To Be Vulnerable Transforms The Way We Live, Love, Parent, and Lead," by Brené Brown. Rankin, a "New York Times" best-selling author, talks about Brown's analogy of marbles in a jar, and how people build, or lose, trust. Using a metaphorical jar, you put marbles in the jar when someone shows you can trust him; you take marbles from the jar if he betrays your trust. This way, you can evaluate how safe your relationship is based on how many marbles are in the jar. The fewer the marbles in the jar, the more you will pull away from your partner. As you pull away, you will stop devoting time and energy to the relationship -- you disengage, which is "the most dangerous in terms of corroding the trust connection," Rankin says.

In the long run, lies and lack of trust breed a lack of authenticity, which disables vulnerability and intimacy. People generally have an innate sense of who is authentic and who isn’t, and people prefer those who are authentic. “When we are inauthentic and try to hide our feelings, others respond physiologically (a rise in blood pressure)," according to the "Psychology Today" article, "Vulnerability, The Secret To Intimacy," by Emma M. Seppala, Ph.D. “When we allow ourselves to be completely open and vulnerable, we benefit, our relationships improve and we may even become more attractive,” Seppala writes. Seppala also quotes Brené Brown, explaining that people feel comfortable around authentic people, because authentic people also show vulnerability. “Someone who is real and vulnerable gives us the space and permission to be the same,” Brown explains.