Ok, this is really dirty but there have already been multiple blowjob jokes so I figure the nsfw train has left the station.

Country girl walks up to her father and says "Dad, can I borrow the truck?" Dad says, "sure but you know what you have to do."

Girl says, "But I don't want to give you a blow job."

Dad says, "rules are rules."

So the girl reluctantly gets down and starts to give him a blowjob when she says, "Ugh dad, your dick tastes like shit."

Dad says, "That's right, I forgot your brother already borrowed the truck."