One of the most important things you can do in any relationship is adjust your listening style. It will change the way he relates to you almost instantly. Have an actively listening style, and get him to talk to you about things he rarely gets to talk about at length. What you really want is for him to feel perfectly safe telling you almost anything.
Here's why: The more you listen to him, the more he will open up. When you let him open up to you, you accomplish several results: First, by allowing uncritical listening, you allow him to feel extremely comfortable around you. Helping your perspective mate feel comfortable is one the most important things you can do, and will have him to want to be around you often.
And then there is another effect. It is called transference, and it is a powerful phenomenon. You may associate Sigmund Freud with this term or a psychology class you remember. Sigmund Freud coined the term and studied its effects at length after so many patients confessed their love to him during therapy. Freud ended up putting a screen between him and his patients - it didn't help. Several types of professionals experience this all to common phenomenon today.
This happens for a few reasons: Unburdening themselves was pleasurable because it alleviates stress, but more importantly it was the 'transference of affection'. As your man is divulging his personal history, thoughts, actions and desires, the affection he holds for these is being transferred to the listener. In the same way that therapists, counselors, clergymen and other professional who spend time listening uncritically find themselves the object of much affection, you can use this principle to make a substantial and positive effect on his feeling towards you. The term transference actually refers to transference of feelings. By talking about life's activities that produce heartfelt emotion, the feeling is transferred from the previous event, to the present. You are the both catalyst and the present entity while this transference of emotion takes place, and the feeling become associated to you. Similarly when men talk about a very pleasant subject, namely themselves, the affection for that subject then transfers to the catalyst once again and translating into love for you. Just by listening to him, you can open up his affection for you, and keep it. Make no mistake about it, he needs someone who he can talk to, and you want to be the one.
Here's how to make it work for you: Begin your uncritical listening by asking open-ended questions. These are questions that are not easily answered with a 'yes' or 'no'. Start with questions that are related to current situations in his life that you sense he is interested in. If you barely know him, this will be the easiest way to get him talking. Once he gets used to talking, start with asking him open-ended questions about his childhood, his parents, how he feels about his job, the people he's close to. Try to mention the questions casually so that he doesn't feel investigated, as he is not used to people being so interested and listening so intently. The fact that he is not used to this, is a benefit because it creates a uniquely satisfying interaction that he wants and needs, but it may take time before he is able to really ready to talk openly about his feelings.
For instance, you walk by a house and say, "wow that house is so similar to mine, it reminds me of being 5 years old." What was your house like when you were 5. When he answers, don't rush to comment. Make it clear that you are listening but don't try to liken the situation to yours, your main purpose now is to get him to keep talking. Even if he answers with short answers at first, just keep listening, and he will start talking more. These are the type of questions that are good to get him to talk : Who are his favorite relatives? Why When did he first think of becoming a(n) (his occupation)? Why? What are some of the things he is proudest of in his life? What are these accomplishments? What was he like as a little boy? How did he get along with his siblings?
Well, you get the idea. Everyone likes to talk about his or herself. That's just human nature. By being the one he knows he can talk to, you make yourself an important part of his life.