The morality of telling the lie is on a case by case basis. In some situations, it might be better to tell the truth, and according to utilitarianism that would then be the moral action. Unlike Kantian philosophy, one is not bound by an immutable universal law. Instead one must judge in each case which action will produce the most overall happiness. The problem with this approach is that morality loses any value as a universal or intrinsic quality.
Every decision is made on an individual basis in an individual and specific situation.
Defenders of utilitarianism claim that it maintains universality by considering the greatest happiness of all beings, rather than just individual happiness. Still, the morality is based on constantly changing and often unpredictable consequences. Although utilitarianism often offers the easier solution to perform because it produces immediate gratification and allows many exceptions to common sense moral codes, the answers it gives are unfilling and unrealistic. Furthermore, it is difficult, if not impossible, to make all of the required calculations beforehand. Kant's solution, although as interpreted by Kant is sometimes overly extreme, is much better than utilitarianism.