The first sentence means that the uncle is jerking a horse's dick. The second one means that the speaker is helping his uncle named Jack off of a horse's back.
In the first sentence, Uncle is capitalized, because it is a family word used in stead of the person's name, and jack is not capitalized, because in that sentence, it is not the uncle's name, rather it is a verb and Uncle is jacking the horse off.
In the second sentence, uncle is no longer capitalized, because his name is specified right after: uncle Jack. Now, since "Jack" is referring to the uncle's name, the action made by the uncle changes from jacking the horse off to being helped to get off of the horse.
2023-03-28 22:26