It is increasingly common that many couples opt to develop a full, stable and robust coexistence out of wedlock, even reaching to have children in common. Therefore if the relationship ended by break, could generate a degree of uncertainty in relation to the rights of the parent with respect to those little. The recognition of children by unmarried parents in most of the countries, in the field of couples occurs an automatic recognition of paternity, in such a way that when the couple has a son regulations understands automatically and a priori (except further proof to the contrary), that this is the son of the mother’s husband. However, the issue is more complex in the field of the couple is unmarried, being common regulations to compel the parent to carry out an express recognition of paternity before the public authorities (in the Spanish case, before Civil registration, registering it in the corresponding book of family). From then on, the position of that parent is equated to the married father, emerging to him all rights and obligations of parenthood. Thus, at least in a theoretical way, there would be no problem when it comes to affirm its position with respect to the small fruit of their relationship (or even outside of it, as there are multiple cases of parents who recognize children born without a link to the mother, or broken once this). The problem that arises in these cases the problems usually arise when breaks the relationship between father and mother, especially if the dynamics between the two suffered heavy wear prior to rupture and shocks, tensions and open discussions were given. The serious problem of this type of situation could be that confrontation with the mother end up affecting the bond that keeps the father with his son. It is not uncommon that, in moments of rage, use children as weapons to do harm to the father, located in practice in a position of clear inferiority with respect to the mother.