The true cause of the peculiar disgust which we conceive for the appetites of the body when we see them in other men, is that we cannot enter into them. To the person himself who feels them, as soon as they are gratified, the object that excited them ceases to be agreeable: even its presence often becomes offensive to him
 Adam Smith, The Theory of Moral Sentiments (1759). copy citation

Context

“According to some ancient philosophers, these are the passions which we share in common with the brutes, and which having no connexion with the characteristical qualities of human nature, are upon that account beneath its dignity.1 But there are many other passions which we share in common with the brutes, such as resentment, natural affection, even gratitude, which do not, upon that account, appear to be so brutal. The true cause of the peculiar disgust which we conceive for the appetites of the body when we see them in other men, is that we cannot enter into them. To the person himself who feels them, as soon as they are gratified, the object that excited them ceases to be agreeable: even its presence often becomes offensive to him; he looks round to no purpose for the charm which transported him the moment before, and he can now as little enter into his own passion as another person. When we have dined, we order the covers to be removed;” source