Did you move to Indiana with your stbx? How recent was this move?

BTW, his telling you that he's going to take the kids because he works simply isn't going to work.

I was a stay at home mom when my ex and I split. The kids stayed with me.

Consult with an attorney in your area about your issues (one of them being where jursidiction is if you aren't considered residents of Indiana yet), once the two of you aren't living together anymore, child support will be ordered.