Unfortunately I'm away from my computer today so I won't be able to fully answer your question as i would like to. But please see my previous AMAs on the subject and feel free to ask anything here and I can try to follow up next week. AMA History of Pornography

AMA History of Libertine Literaute and Pornography

AMA History of Sexuality

There was a hell of a lot of Classical Greek erotic painting on vases. In the classic (but now somewhat dated) Greek Homosexuality Dover writes that "we cannot fail to notice how greatly male pinups outnumber female at the beginning of the classical period".

There are lots of vase paintings of sex acts. Like, so many. All sorts of sex acts, too: men and women masturbating (women with olisboi, which are essentially dildos), M/M sex, M/F sex (anal and vaginal), fellatio...

Here is a red-figure pot depicting M/M anal sex (the image is in fact of the rape of Ganymede by Zeus, you can read Ganymede's name in the image). The receptive partner is holding an olisbos.

Here is a woman masturbating with one olisbos and holding another.

Here is a man having sex with a prostitute (note the money pouch at the top of the image).

Another sex scene. Some more.

There was also written erotica in the classical world, though largely it doesn't survive. The Suda has a tradition that Astyanassa, one of Helen of Troy's maids, was the first writer of erotica, and we know of other sex manuals, for instance, that of Elephantis, though they don't survive.