From Paul C. O'Bryan:
The Ct. of Appeals, in S.R.D. v. T.L.B., 174 S.W.3d 502 (Ky. App., 2005) discusses the theory of paternity by estoppel. I think the "best" chance (absent a new statute) is to argue that if a court can force a father from denying (when he is not the biological father) to get out of child support why can’t the mother be estopped from denying paternity (or “legal” paternity) of the only father the child has known for 8 years.
The court set out the factors of the doctrine of equitable estoppel: “(1) Conduct, including acts, language and silence, amounting to a representation or concealment of material facts; (2) the estopped party is aware of these facts; (3) these facts are unknown to the other party; (4) the estopped party must act with the intention or expectation his conduct will be acted upon; and (5) the other party in fact relied on this conduct to his detriment.”
1) Mom’s conduct concealed the fact
2) Mom was aware he was not the biological father
3) Neither Junior nor Dad knew the truth
4) Mom knew that Dad would act upon this lie
5) Both Junior and Dad relied on the lie to their detriment (both emotional and financial)