Where do you draw the line between deadbeat dad and victim of deceit?

This is an easy question in Japan, where I am living. There is no law about child-support. If you are living with the woman, you have to take care about ALL children with both of you in the same household - you are the biological father or not does not matter.

If you divorce or separate - married or cohabitation is not a criteria - you have no visitation rights as father, and on the other side no obligations to pay anything. Usually children will stay with the mother.

You want to see the children, who continue to live with the woman - your children or her children not does not matter - it is the custom here in Japan to offer some support money in return.

You must simply said arrange that all with the woman - there is no legal way to force payment from the father and to force visitation rights from the mother.

As woman in Japan you are better off not to cheat your boyfriend to become a father - the 'father against his will' might refuse to pay anything and just leave...moving away, forget about his past, problem finished for him.