I say, and with Allah's guidance: The lineage of the fetus is denied if he denies it by denying the lineage, by saying: You are an adulteress and your child is not mine. As for the denial of lineage only by the accusation of adultery, the lineage is established with it. If the denial of lineage is valid, it is not permissible to marry her until one of them contradicts what he said in the denial of lineage. And Allah knows best.