Responsibility Towards the Child of Fornication
Question

                AsSalaamu Alaikum.
Before I accepted Islam I committed adultery an conceived a child with a married 
woman. The woman's husband has been told the truth and is aware that the child is 
not his, but he still wants to keep the child and his wife. Her husband wants to have 
nothing to do with me(understandably) and wishes that I keep away from my son 
who I have rarely seen and he does not know who I am. The child is almost 3 years 
old and I have been a Muslim for almost 2 years. 
What is the Islamic ruling in such a case? Can I consider the child to be mine?
The husband and his wife are both kaffirs.
Praise be to Allah.All Praises are Due 
  to Allah
Islam erases whatever 
  took place before it and after Allah guides you there is no sin on you, regarding 
  something which took place in the past. The rule according to the Shariah (Islamic 
  Laws) is that the child is to the bed and follows the husband, unless he washes 
  his hands of the matter.
The child in not 
  considered to be your son, nor do you have any responsibility for him. So start 
  a married life according to Islam. 
May Allah forgive 
  you and increase you in protection.