At the end of the 2nd century, Clement of Alexandria mentions the deification of Antinous in his Against the Heathens c.4 (online here):
Another new deity was added to the number with great religious pomp in Egypt, and was near being so in Greece by the king of the Romans, who deified Antinous, whom he loved as Zeus loved Ganymede, and whose beauty was of a very rare order: for lust is not easily restrained, destitute as it is of fear; and men now observe the sacred nights of Antinous, the shameful character of which the lover who spent them with him knew well.
Why reckon him among the gods, who is honoured on account of uncleanness? And why do you command him to be lamented as a son? And why should you enlarge on his beauty? Beauty blighted by vice is loathsome. Do not play the tyrant, O man, over beauty, nor offer foul insult to youth in its bloom. Keep beauty pure, that it may be truly fair. Be king over beauty, not its tyrant. Remain free, and then I shall acknowledge thy beauty, because thou hast kept its image pure: then will I worship that true beauty which is the archetype of all who are beautiful.
Now the grave of the debauched boy is the temple and town of Antinous. For just as temples are held in reverence, so also are sepulchres, and pyramids, and mausoleums, and labyrinths, which are temples of the dead, as the others are sepulchres of the gods.
He then goes on to quote the Sybilline oracles. The statement that Antinous was buried at Antinoupolis, if not rhetorical, is interesting.