Most have heard of the Kama Sutra, the ancient Indian sexual manual, describing all sorts of sexual activities and positions.
The Kama Sutra dates back around 2,000 years. However, there is a possible sex handbook (or flat out ancient porn), with illustrations, that dates back over 1,000 years BEFORE the Kama Sutra...
It is the Erotic Turin Papyrus; a strange series of ancient Egyptian drawings generally showing men with very large cocks having sex with young women in all sorts positions. (But also showing Female Masturbation as well.)
For more on the Turin Porn Papyrus, see the article below:
"Bringing Sexual Awareness to the Global Consciousness."
Can't really say size doesn't matter when even way back then Big Cocks rule. Even if not intentional this is basically ancient Small Penis Humiliation/Shaming lol.