You're probably thinking of (one variation of) Rule 34: "Rule 34: If you can imagine it, it exists as Internet porn." https://en.wikipedia.org/wiki/Rule_34#

You're probably thinking of (one variation of) Rule 34: "Rule 34: If you can imagine it, it exists as Internet porn." https://en.wikipedia.org/wiki/Rule_34#Variations https://en.wikipedia.org/wiki/Rule_34#Variations