Her brother Steven

"Oh Steven......I...I didn't hear you come in." Cassey said blushing as she quickly pulled her little thong and short shorts back up to cover herself up. She was surprised to see anyone else in the ship's zoo.

The 5'4" blonde haired, blue eyed 18 year old hoped her big brother hadn't seen too much as she hurridly zipped her pants back up.

Steven smiled as he looked over his little sister's curvaceous 37DD-24-35 body. He wished he had kept his mouth shut a little bit longer so that he might have been able to see a bit more of it. It seemed that she was always teasing him and his brother in her sexy outfits while on the spaceship.

Today, for example, the busty teen was wearing a pair of skin tight white short shorts and a neon pink halter top. It was obvious she wasn't wearing a bra underneath, as her nipples were clearly visible pressing against the stretchy material. The top of her pink thong was peaking out above her shorts. On her feet she was wearing a pair of white pumps, that showed off her shapely tanned legs, along with a silver anklet on her left ankle.

In reality, Cassey was totally innocent and completely unaware of the effect her amazing body had on men, including her own brothers'.

Cassey looked over Steven's muscular body covered by his skintight jumpsuit. She couldn't be sure but it seemed as if he had a bulge in the crotch of his suit.

The muscular 23 year old stepped behind his little sis as they both watched the monkey like creature fuck one of the females from behind.

"If you have a few minutes I was wondering if you might help me feed Yugo?" she asked Steven.

Yugo was a new addition to the zoo they had just gotten a few weeks ago. The massive 600 pound gorilla like creature stood well over 7 feet tall.

Steven remembered that Yugo was fairly aggessive towards males but seemd to calm down whenever Cassey was nearby. He recalled that the powerful animal had two 15" cocks swinging between it's massive legs.

He smailed as he looked over his little sister's curvy body in her sexy outfit and said, "Sure."

"Great!" replied Cassey as she led Steven through several doors towards Yugo's special cage.

Steven couldn't take his eyes off his little sister's sexy butt as he followed her down the corridors. He enjoyed the sight of her ass wiggling as she strutted down the hallways with her high heels clicking on the steel floor.

What happens next?????