I am not married, so I'm a bit of interloper here.
Sounds to me like you really don't want to go back to being a parent of young children.
"My role is to think they
Yes, we have talked, and waht he wants is for me to be the "fun aunt."
Maybe it is just a matter of clarifying with HIM what HE expects from you with the kids ... you know? Where does HE envision you in their lives - is it just a peripheral role? Or does he want you to step in and parent???
I think in my last relationship, I was pretty comfortable being the "fun aunt" and just kind of letting him do all the work of parenting - but he was expecting me to be more of a replacement MOM to them, you know? I think that really was a big part of our demise.
Clarify HIS expectations. There is a reason your intuition is flaring up - listen to your inner voice. It's trying to tell you SOMETHING!
When it comes to "him and I", there is no money (or so he says)... He does nothing special for US.
Since there are a lot of days when he isn't w/ his kids, what is his excuse for not doing things w/ you then?