on Jane Friedman site:

When writers think of writing intimate scenes, our minds often go straight to the bedroom—to romantic or sexual intimacy. But that puts an unnecessary constraint on what intimacy is when intimacy can be physical or emotional, platonic or romantic. At its simplest, intimacy in a relationship is the state of closeness or deep familiarity. Regardless of what their relationship is, emotional intimacy between characters often begins long before they get physically intimate (if they ever do) and some level of emotional intimacy belongs in every close relationship.

No matter what you’re writing (even if it’s not romance), emotional intimacy between characters is important to creating authentic relationships and creates the backbone for deep relationships between characters and readers.