5 Answers

In cases when the father of the child is not known, a fatherhood (paternaty) DNA test is the way to varify who the father is.

When you put the child on your shoulders and it wees or throws up down you neck.

There's an old expression that goes .......'' It's a smart child that knows it's own father "  That means no one ever knows for sure who his / her father is.........unless there's a DNA test. That's what marriage is for.......to determine who the father  of a child is. The law presumes that the husband of the woman is the father of  any child that she has delivered within  in the confines of that  marriage. That law was made way before DNA was discovered.

Run away, be happy... Unless of course the baby insists on calling you daddy. 

Anyone who can produce male gametes, can be a father.  Only men who step up and take care and love can be "dads", you decide which it will be!  Or the lawyers will with the tests...