repost of the beginning of that story
the barn was silent for a few minutes, until the clop clop of hooves broke it. he could tell applejack was right out there, her sexual urges taking over her logical mind...her hips aching and body hot, her....oh no
for what felt like the hundredth time this morning, big mac began panicking...he started thinking about granny smith, cold water, and an assortment of ideas and images passed through his head, but to no avail...
"damnitall" big mac mumbled to himself as his erection grew...a more educated mind would know this was simply due to pheromones...but big mac is not educated.
in her single-minded state, it did not take long for her to notice the black...thing poking out of the bale of hay, and big mac yelped in suprise when he felt something warm and wet on his tip.
"mmm..."applejack enjoyed the taste, and big mac did not want to move or startle her...one of his favorite body parts dangerously close to rows of teeth.
in a moment of clarity, big mac got an idea.
"sis, turn around a second" he said simply, he didn't have to bother with phrasing or other word-play...in this mood, applejack was easy to talk to.
and just plain easy, applejack exposed herself to big mac, patiently waiting for her older brother.
what she got however, was much shorter than she expected, but more maneuverable. big mac began eating his sister out, figuring this technically wasn't incest...and if he was lucky, would tire her out before things escalated
big mac was sure this would scar him for life, but it was better than the alternative...
a few minutes after they began, applejack fell to the ground, her legs like jelly and her tongue hanging out the side of her mouth. she was in no condition to run, and big mac used this to his advantage. he took off from the barn, spitting the...juices out of his mouth, and making promises to celestia to redeem himself for the sin he just commited.