If we are to preserve our modesty we must avoid fellowship with profligate men, also the banquets of strangers, and intercourse with women; our leisure time at home should be spent in pious and virtuous pursuits.
85. Modesty has indeed its rocks— not any that she brings with her, but those, I mean, which she often runs against, as when we associate with profligate men, who, under the form of pleasantry, administer poison to the good. And the latter, if they are very constant in their attendance at banquets and games, and often join in jests, enervate that manly gravity of theirs. Let us then take heed that, in wishing to relax our minds, we do not destroy all harmony, the blending as it were of all good works. For habit quickly bends nature in another direction.
86. For this reason I think that what ye wisely do is befitting to the duties of clerics, and especially to those of the priesthood— namely, that you avoid the banquets of strangers, but so that you are still hospitable to travellers, and give no occasion for reproach by reason of your great care in the matter. Banquets with strangers engross one's attention, and soon produce a love for feasting. Tales, also, of the world and its pleasures often creep in. One cannot shut one's ears; and to forbid them is looked on as a sign of haughtiness. One's glass, too, even against one's will, is filled time after time. It is better surely to excuse oneself once for all at one's own home, than often at another's. When one rises sober, at any rate one's presence need not be condemned by the insolence of another.
87. There is no need for the younger clergy to go to the houses of widows or virgins, except for the sake of a definite visit, and in that case only with the elder clergy, that is, with the bishop, or, if the matter be somewhat important, with the priests. Why should we give room to the world to revile? What need is there for those frequent visits to give ground for rumours? What if one of those women should by chance fall? Why should you undergo the reproach of another's fall? How many even strong men have been led away by their passions? How many are there who have not indeed yielded to sin, but have given ground for suspicion?
88. Why do you not spend the time which you have free from your duties in the church in reading? Why do you not go back again to see Christ? Why do you not address Him, and hear His voice? We address Him when we pray, we hear Him when we read the sacred oracles of God. What have we to do with strange houses? There is one house which holds all. They who need us can come to us. What have we to do with tales and fables? An office to minister at the altar of Christ is what we have received; no duty to make ourselves agreeable to men has been laid upon us.
89. We ought to be humble, gentle, mild, serious, patient. We must keep the mean in all things, so that a calm countenance and quiet speech may show that there is no vice in our lives.
Source: On the Duties of the Clergy (New Advent)