Love is a strange emotion in that it has highs and lows and it is never constant. Marriage is a big commitment. I would not pretend to know what is going on with him, but his hesitancy could be due to any of a number of reasons. Maybe he s concerned about the future, his family, who knows unless you talk about it. If you are sure he is the one and you are secure in that I would focus on helping him reach the same level of commitment. You can do that best by love rather than nagging or ultimatiums GOOD LUCK - I am rooting for you!