In life insurance interpleader action, district court properly awarded proceeds to decedent’s son over the objections of decedent’s sister who claimed that decedent was homosexual and was not the father. Illinois Parentage Act created presumption that decedent was natural father to alleged son, where decedent and son’s mother had signed acknowledgement of paternity. Moreover, sister’s allegations regarding homosexuality of decedent was not conclusive evidence that decedent could not have been father of alleged son.