There is no way that I would sign a Birth Certificate without a DNA Test.

Being a parent to a child is the biggest responsibility that a person can partake.
The woman obviously knows that the kid is hers, but the boyfriend/husband has no way of knowing if it's his without the DNA test.
With the amount of cheating that goes on even in marriages a guy would have to be naive to just trust that the kid is his.
And most guys don't ask for the DNA test because they are afraid that their wife will get mad.
If she is angry about you wanting to assure that the kid is yours then it's likely that the kid isn't yours, or she isn't sure if it is yours.
There are legal time constraints to paternity that determine if you are on the hook for 18 years or not.
Besides, why would a husband want to waste his time/money raising her side pieces offspring, not to mention being married to a whore that cheated ?
Don't be a wuss and cower to the females that will bash you for demanding the DNA test because none of those broads will be helping you pay child support for a kid that isn't yours.

Anyone that downvotes this is either a loose woman or a simp that is blinded by his lack of experience with women.