Fear of losing friends. The marriage bond, according to many men, imposes certain obligations that are able to alienate him from the faithful and loyal companions. Men sometimes attach great importance to the friendship. And a hint of the fact that now he will have to spend in the company of a loved friend over a beer in much less time, is able to bring him in horror. Over time, let them know a loved one, it is not so, and you are not going to separate him from his friends.
Fear of love repeat failure. Perhaps one day your partner has had a bad experience in personal relationships that associate it with discomfort, and now he fears a repetition. In this case, before you make an offer, it will be a long time to learn you to make sure that you are different from the previous pass. Be patient and wait quietly until your man will be decided on this myself.
Doubt that in love you truly, that you - that the woman with whom he will be happy, and that will give him children. Yes, he likes to spend with you in the evening and weekends, you have great sex. But to live together, he is not ready yet. Perhaps his heart is not yet fully open to love. It is better to give him time for him to sort out their feelings and understand what he wants.