I am not trying to be mean but what is his incentive to marry you. Ask a married man why he maried his wife and most of the time they'll say they wanted them around all the time or he wanted to have a family with this woman. But he has already getting all of this with you without being married. Because of this I think you need to let him know that this is something that is bothering you. You already live as married people do so ask him straight out " when if ever does he plan on marrying you and what has been the hold up" If you don't mention it what is to lead him to the believe that you have a problem with the way things are going.? You have to at least give him the chance by conveying how you feel and leaving the ball in his court after that. Do not tell him what your time frame is but you should have a firm one in mind after you discuss your feeling and stick to it. Men can be very oblivious at times let him know how you feel.