The toughest part about intimacy is the fact that you have to trust your partner absolutely and unconditionally. The reason for this is that being truly intimate with someone you love, you have to expose yourself to such an extent, that you feel completely naked. I do not mean physically, but emotionally exposing yourself. True intimacy in a mature relationship is not only physical. To be truly intimate, you have to tear down your proverbial walls to allow that person to look into your soul, and to become one with them. Take a look at this article about intimacy
