It sounds like you are not really "in love" with this guy any longer. At ages 25, I think you are both too young to *settle* for such a lackluster relationship. Yes, there are risks involved in leaving. No doubt, he would be very hurt, if you ended the relationship. But, it's better for him to go through that now, rather than in 10 or 20 years. He sounds like a good guy who deserves to find a woman who will feel lucky to have him. He deserves a chance for that to happen. Some woman will be thrilled to get him, if he just manages to hold down any job. You will be perpetually disappointed in him. His lack of drive will not change.

Maybe you two started living together without really knowing each other. But now you do really know each other. You're both decent people. Neither of you is doing anything wrong. That's all not a good enough reason to get married. It sounds to me like you will always feel somewhat cheated, if you stay with him. That won't be good for either one of you. You will constantly be prone to comparing him with other men you meet who show more drive.

You recognize that leaving him is risky for you. There's no guarantee you'll transfer smoothly into a better, more fulfilling relationship. Personally, I think it's kind of cruel for a woman to hold onto a man she's not head-over-heels in love with, just because he's safe and dependable . . . . . unless she is totally willing to permanently commit to him. Otherwise, the poor guy ends up getting dumped some day, when his wife does fall hard for someone else. The husband is blindsided because he never knew his wife's true feelings. That's terribly unfair.