From
catholic.com/tracts/early-teachings-on-homosexuality
Some argue that neither the Bible nor apostolic tradition condemns the practice of homosexuality. Passages such as Leviticus 18:22–30, Romans 1:26–27, 1 Corinthians 6:9, and Jude 7 serve as ample proof that Scripture indeed condemns homosexuality. Below is ample proof from tradition. The Fathers are especially harsh against the practice of pederasty, the homosexual corruption of boys by men.
The Didache
“You shall not commit murder, you shall not commit adultery, you shall not commit pederasty, you shall not commit fornication, you shall not steal, you shall not practice magic, you shall not practice witchcraft, you shall not murder a child by abortion nor kill one that has been born” (Didache 2:2 [A.D. 70]).
Justin Martyr
“[W]e have been taught that to expose newly-born children is the part of wicked men; and this we have been taught lest we should do anyone harm and lest we should sin against God, first, because we see that almost all so exposed (not only the girls, but also the males) are brought up to prostitution. And for this pollution a multitude of females and hermaphrodites, and those who commit unmentionable iniquities, are found in every nation. And you receive the hire of these, and duty and taxes from them, whom you ought to exterminate from your realm. And anyone who uses such persons, besides the godless and infamous and impure intercourse, may possibly be having intercourse with his own child, or relative, or brother. And there are some who prostitute even their own children and wives, and some are openly mutilated for the purpose of sodomy; and they refer these mysteries to the mother of the gods” (First Apology 27 [A.D. 151]).
Clement of Alexandria
“All honor to that king of the Scythians, whoever Anacharsis was, who shot with an arrow one of his subjects who imitated among the Scythians the mystery of the mother of the gods . . . condemning him as having become effeminate among the Greeks, and a teacher of the disease of effeminacy to the rest of the Scythians” (Exhortation to the Greeks 2 [A.D. 190]).
“[According to Greek myth] Baubo [a female native of Eleusis] having received [the goddess] Demeter hospitably, reached to her a refreshing draught; and on her refusing it, not having any inclination to drink (for she was very sad), and Baubo having become annoyed, thinking herself slighted, uncovered her shame, and exhibited her nudity to the goddess. Demeter is delighted with the sight—pleased, I repeat, at the spectacle. These are the secret mysteries of the Athenians; these Orpheus records” (ibid.).
“It is not, then, without reason that the poets call him [Hercules] a cruel wretch and a nefarious scoundrel. It were tedious to recount his adulteries of all sorts, and debauching of boys. For your gods did not even abstain from boys, one having loved Hylas, another Hyacinthus, another Pelops, another Chrysippus, another Ganymede. Let such gods as these be worshipped by your wives, and let them pray that their husbands be such as these—so temperate; that, emulating them in the same practices, they may be like the gods. Such gods let your boys be trained to worship, that they may grow up to be men with the accursed likeness of fornication on them received from the gods” (ibid.).
…
“In accordance with these remarks, conversation about deeds of wickedness is appropriately termed filthy [shameful] speaking, as talk about adultery and pederasty and the like” (The Instructor6, ca. A.D. 193).
“The fate of the Sodomites was judgment to those who had done wrong, instruction to those who hear. The Sodomites having, through much luxury, fallen into uncleanness, practicing adultery shamelessly, and burning with insane love for boys; the All-seeing Word, whose notice those who commit impieties cannot escape, cast his eye on them. Nor did the sleepless guard of humanity observe their licentiousness in silence; but dissuading us from the imitation of them, and training us up to his own temperance, and falling on some sinners, lest lust being unavenged, should break loose from all the restraints of fear, ordered Sodom to be burned,
pouring forth a little of the sagacious fire on licentiousness; lest lust, through want of punishment, should throw wide the gates to those that were rushing into voluptuousness. Accordingly, the just punishment of the Sodomites became to men an image of the salvation which is well calculated for men. For those who have not committed like sins with those who are punished, will never receive a like punishment” (ibid., 8).
Tertullian
“[A]ll other frenzies of the lusts which exceed the laws of nature, and are impious toward both [human] bodies and the sexes, we banish, not only from the threshold but also from all shelter of the Church, for they are not sins so much as monstrosities” (Modesty 4 [A.D. 220]).