Well considering the looks of it, how weman who are married to their husband's still go out side to get satisfaction I would say it's clear that DNA test should be done because how will a man actually fill training another's man child only to find out it was not his child .ah that is really evil for a married woman who consider doing such tabu .

Well it's clear in link ,that DNA test should be conducted in a family.  because one thing is for sure a child takes the characteristics of his parents  biological or not. so it will be hard to tell physically but there nothing science can't prove.
 
Yes to DNA test