Applejack was horny.
But it didn't bother her. It never lasted long.
She was constantly sleeping with her friends. Rarity, Rainbow Dash, Pinkie Pie, and sometimes even Fluttershy.
She would be open to sleeping with Twilight too, if she ever asked. But Twilight never did.
One of them would visit on any given day. They would flirt during Applejack's farmwork until she gives in and takes a break. Then they'd find a private spot.
Applejack didn't know why, but her friends were all madly in love with her rustic country charm. Or perhaps it was her strong, toned body. Or her blonde mane color. Her homemade apple-based snacks probably helped too.
The sex was always great. Then there would always be some argument over a trivial issue. The partner would get upset over Applejack's stubborn opinions, then leave in a rage. Every single time.
They'd always return next week, wanting to make up and get intimate again.
Applejack didn't understand her relationships at all.
But life seemed to work out, so she didn't question it much.