If you are the type of person that sticks to trying out different boys and moving from one to the next relatively rapidly and you dream that you have a steady boyfriend, this suggests that you are getting tired of these types of relationships secretly. They are unfulfilling to you and you want to move onto something a little more mature. A real boyfriend would do this for you. They would love you and respect you for who you are.
To dream that one of your closest friends is your boyfriend suggests that you have deep feelings for this person, but does not necessarily suggest romantic feelings. By all means it is definitely possible and even likely that your friend is trying to impress you and trying to get to know you a little better romantically. You are picking up on this subconsciously and projecting that into your dreams. It is also possible that a dream like this is a reflection of your personal desire to see a romantic relationship develop between you and your friend. You want to meet him and be able to date him.
It is just as equally likely though that the feelings are unromantic. The dream that you are having is really suggesting that you need to have a more open relationship with your friend. You are not letting him know everything about you and sometimes not being as open or as honest as you should about certain things. To dream that he is your boyfriend suggests that you have reached a level of comfort with him that would make I appropriate for you to continue your relationship by reaching him on an even deeper level now. You need to really get to know him like you haven’t gotten to know him before, and you need to let him get to know you too.
If you are a boy, to dream that you are someone boyfriend suggests that you have a strong affection and a desire to be with someone. This is different than a sexual desire. If you wanted to have sex, your dream would be a sex dream. A dream like this suggests you want something more out of a relationship than just sex. You want to be able to have someone to give all of your affections to and trade love with. Affection and real love is just as important to you as sex if not more so at this critical juncture.
Being a boyfriend is about being there for someone and really being able to comfort them. To dream that you are this suggests that you are ready for that type of relationship. It also suggests that you have probably had a recent spike in maturity, as it would take someone very mature to display this type of emotional response to anything. Congratulations on your new found adult feelings and your feelings of love.