Eveready Harton in Buried Treasure (1929) - first animated porn
This is pretty graphic, but hilarious. 7 mins.
You can't get to the board on MC, but it's on Imdb: https://www.imdb.com/title/tt0306606/
Watch or download MP4: https://archive.org/details/EvereadyHartonInBuriedTreasureSD