In old Colonial south, Alabama, Mississippi, Georgia and other states where female Mules and Mare's were used for field work the young men tending these farm animals would often find a suitable height stump around the edge of the field they were working and back the animal up to their penis and give it a good flogging. These young men far removed from female companionship would take large melons and gourds from the field and cut a small hole in the vegetable into which they would insert their penis and have sex with the still sun warmed vegetable.
Ole Jimmy, Hell that boy is a stumpjumper. His momma caught the old mare backed up to him last week when the morning fog suddenly lifted off of the bean field.
You show dont want to eat no watermelons that Bobby Lee offers you. His daddy caught him up in the hay loft with a big ole striped watermelon the other day, he was laying into that poor old watermelon like a damn buck rabbit on a doe, Pluck! Went his dingus when his daddy started screaming!