True intimacy, as defined in the frame work of Mindful Compassionate Dialogue, lives in a container of acceptance, mutual care, mutual respect, and healthy differentiation. You can "feel close" to someone through a rush of love chemicals, enmeshment, or a trauma bond, but these kinds of experiences typically involve meeting some needs at the cost of many others and are not sustainable over time.
Intimacy is something that grows and deepens over time, when each person is able to experience and trust a sense of acceptance, mutual care, and mutual respect. In this case, sharing one's experience of life becomes a regular and satisfying part of relationship.
While reporting the details of what happened in your day likely creates some sense of connection, intimacy is accessed when you share your experience of life. Your experience includes: feelings, needs, impulses, thoughts, energy, dreams, hopes, mourning, etc. The more of these types of experiences you can share and have received, the more intimacy is created.
Talking about what others did or said or just the things you did, leaves the other person guessing at your experience. In that case, rather than make explicit guesses they might simply focus on the events of your day and maybe collude, try to problem solve, or rely on unspoken assumptions.
Sharing at the level of your experience with depth and subtlety, requires you to be self-aware and to hold your experience as valid regardless of another's response to it. This is part of healthy differentiation. When you are self-connected and self-compassionate, you can share intimately. When you are adjusting what you share in hopes of influencing how another thinks or feels about you, intimacy remains blocked. And, of course, if the other person isn't able to receive your experience with care, acceptance, and respect, intimacy is blocked.
With these four foundations of intimacy: acceptance, mutual care, mutual respect, and healthy differentiation; intimacy grows over time in a trusted relationship. It becomes rich and nuanced, and full of discovery.
Relationships begin to fall apart when this level of being seen and heard in intimacy is no longer available. Losing that "loving feeling" is a symptom that intimate sharing is no longer prioritized. Letting parenting, work, protecting one's autonomy, or defending against old wounding, take center stage, leaves little room for the aliveness and warmth that comes from intimacy.
In desperation to be seen, heard, and known you find yourself searching for someone who offers that. Without the ability or skill to face what's happening, affairs are often the result.
Healthy differentiation is required for sharing intimately and for listening intimately. Listening intimately means being able to set aside you ideas and agendas for the other person, and hold quiet space of presence for them to unfold into. This often means that intimate conversations are slower. Since you are not preparing what you want to say while the other person is speaking there is often a pause between each bit of sharing as attention moves back and forth between the other's experience and your own. Holding presence implicitly recognizes that no matter how many years you have "known" someone, their experience in the present moment is utterly new. Listening and speaking with presence, intimacy is the preciousness of being in touch with another's aliveness as it is revealed in the moment.
Practice
The next time someone close to you begins to share intimately, practice offering presence by relaxing your places of tension in your body, resting a soft curiosity on the other's sharing, and quieting your own thoughts and views.