Am I his girlfriend or mother?

been with my bf for several years and we are generally compatible except when it comes to $.

He has only a small amount of assets, I don't.
He only earns a modest salary, I don't.
I am an avid saver, he isn't.

but...we are compatible in many ways like

interests
family
personality
sex

I can't help myself, when I see him going off track financially and any financial obligations, I speak up and try to do so nicely but firmly. I feel like his mother and only say something when it really bothers me. He knows I know his bank account information thinking that would make me feel better but it doesn't.

He wants to live with me but all of this has put it on hold.

He sometimes compliments me "for helping him being a better person and being financially responsible" and other times carries a chip on his shoulder if I shame him (in a nice way). I am very moral and sometimes I just feel he is not, it's that simple.
I know we should love someone for who they are but what happens if you know what they are doing is just wrong under anyone's definition?
We do love each other and we are both beyond middle age....do I give up? I don't want to be his mother the rest of my life and want to know my SO is acting responsibly.