Intimacy is having an in-depth knowledge of what each others needs are. There's a difference between intimacy and sexual satisfaction. Sexual satisfaction is pleasing your mate physically but intimacy is having a deep affectionate for them which usually satisfies their emotional needs. It is a quality of being comfortable in your skin as you share a warm embrace or a tender kiss.
Sex is a gift from God that is meant to be share between a husband and wife. Intimacy is a gift from your spouse that is meant to be shared through love and understanding. It provides a sense of closeness and builds a bond that can not be broken.
1Peter 3:7 "Likewise, husbands, live with your wives in an understanding way, showing honor to the woman as the weaker vessel, since they are heirs with you of the grace of life, so that your prayers may not be hindered."