Would you abandon your children if you found out they were not yours biologically?

As the question states, though I would prefer guys to answer this one. An old school friend that I have not seen for years until recently told me he found out that all three of his children were not his biologically. When he found out he not only left his wife, but cut off all contact with whom he had thought were his biological children. What as a guy would you do here? What if you cared about and loved those kids?