This article also explains the "levels of intimacy" (like the book I'd recommended--and the video that describes it). I think this happens very often....that there's a false sense of intimacy due to the couple having sex prior to fully developing the other stages. This article presents it as being a problem that happens when the couple has sex prior to marriage---but I believe it can happen even if the couple had waited until marriage to have sex.
>>>Sex…A False Sense of Intimacy
When you look at the five levels, I’m sure you’d agree that the fifth or highest level is the healthiest, safest and most intimate place to have sex. When we feel loved unconditionally, and have the highest level of trust, we’ll be able to give ourselves completely to each other, increasing intimacy and the enjoyment of sex. We can have sex at the other levels, but without that same level of trust the vulnerability of sex may be associated with anxiety, fear and distrust. As I’ve led women through healing, I’ve discovered that they have the hardest time with sex if they’re not at this highest level with their partner, and if they’ve been wounded by sex with others in lower levels of intimacy, whether through abuse or their own choices.
When we have sex outside marriage before the highest level, we are creating a false sense of intimacy in our relationship. The sex makes us feel closer than we really are. Let’s say we’re at level three, where many couples start having sex outside marriage. We’re only sharing thoughts, opinions and beliefs at this level. Of course we may occasionally move up to the next level as we’re building trust, but until we’ve built enough needed, we’ll always gravitate back to where we feel the safest. The sex makes us feel close, but in reality we don’t know each other very well. We’re experiencing a false sense of intimacy. We’ll use sex to express our love, communicate and resolve conflict. And now it’s at this level of emotional intimacy that we’ll most likely stay.
In other words, emotional intimacy can get stalled at the level where we start having sex. Let me explain why. Emotional intimacy REQUIRES being able to risk conflict in order to move to the next level. Handling conflict in a healthy and safe way without being rejected is what allows us to build the trust needed to communicate at higher, more vulnerable levels. But now that we’re having sex, we feel close, and we won’t want to risk losing them. We also may feel that this is the one, and we won’t want anything to threaten this relationship. And so although we may occasionally move to higher levels,we’ll continue to fall back into that safe zone to communicate. We may sense that there’s something missing, but then with sex, we’ll feel that surge of closeness again, making us feel all is well…~
The Five Levels of Intimacy - FamilyLife Canada