Marriage Proposal

I have been with my boyfriend for going on 5 years. At first, he was dead set against us moving in together, he said he needed his space. We have both been divorced and has some pretty bad experiences in our past relationships. He finally decided that we should move in together over 3 years ago. He has his own bank account and my paycheck goes directly into his account to help with bills and such. I totally trust him. The problem I am now facing is that we bought a boat together last year, this year we have purchased a new truck and a travel trailer together. He is over 50 and I am going on 50 and I think that since we now have so much joint property, we should possibly be thinking about what would happen with the property should something happen to one of us. I really want to spend the rest of my life with him, but he is afraid that getting married would screw things up between us. Would using the property situation aas a logical reason for us to go ahead and get married be wrong? Or should I just propose myself and hope that he is willing to take it to the next level? I totally understand his concerns, but after 5 years with him, I am not planning on going anywhere. Please help!!!!