Most Helpful Guy
Hit the eject button. Be kind about it though. Normally, I would say be 100% honest as to the breakup reason because that is how men learn and become better. However, in this case, you likely should be slightly more vague. For instance, ask him rhetorically something like "Bob (or whatever his name is), what would you do if we were married and I became injured or died and could no longer support us? How would you take care of yourself?" Based on his answer, you can gauge his personality better. If you don't like the answer and it is indicative of a key personality issue, then you can respond that "I just don't see us having a safe future and I need that."
Most Helpful Girl
Ditch him. It might give him a wake up call he desperately needs. If you won't do it for yourself, do it for him; it isn't healthy to be dependent on someone else for everything.