It was a hot summer day at the Ponyville post office & the air conditioner wouldn’t arrived until tomorrow. Derpy was finding her work difficult because of the heat. Even being in her underwear wasn’t working. So she decided to take her bra & panties off & she started feeling better. Then, she started feeling horny & started masturbating on her office chair at the sorting desk & was enjoying herself. Luckily, it was slow day today, otherwise she would have to hide in the bathroom to avoid getting caught.