Humans Sam, Georgie, and Lana were travelling together to get to their destination planet, Arimoth. They were bringing back samples and data to more fully analyze them.
The three were all close friends, and had been since they met as teenagers. Georgie was the youngest of the bunch at 20, but also the tallest at 6'3. Lana was 5'9 and 23, and Sam was 5'5 and 21.
Lana was sitting in a chair reading a book about the planet they had just left. Georgie and Sam were bickering, but jokingly. Lana decided to go to the bathroom to get away from the noise. Anyways, Lana felt the need to pee anyway.
Lana urinated, yet still felt a little weird. A growing feeling of warmth gathered between their legs. Lana felt sexual suddenly, for whatever reason. Maybe they could just orgasm and make the horniness go away. It was more important for Lana to focus on researching than being distracted with feeling sexual. The human sexuality sure was annoying.
Lana masturbated and came as quickly as possible. Despite their efforts to stop feeling horny, the orgasm just made them feel even more sexual. Lana was a little confused and somewhat concerned, since normally they lost interest in fucking after orgasming once. Lana came once more, but the sexual feelings kept building. Lana decided that they'd have to just try to ignore it. They went back to their chair in the main room and started reading again.
Sam and Georgie were now just talking. Lana didn't really wanna feel embarrassed by talking about their current situation, so they kept it to themself.
While in the chair, Lana was discreetly masturbating by rubbing their thighs together. A couple times Lana let out a few small noises, but Sam and Georgie were still too involved in their conversation to notice.
Lana let out a sound of frustration and Sam looked over. "You okay?"
"Uhh, I guess."
"What is the problem?"
"I didn't say there was a problem," Lana replied, sounding a bit annoyed.
"Oh, sorry to bother you," Sam said with a small laugh.
"I think I need to go to the bathroom again," Lana said and went back to the bathroom. Lana fucked themself, again and again. They had lost count of how many orgasms they had had.
"You sure you're okay?" Sam asked from outside the bathroom.
"Oh fuck," Lana hissed, and then said, "Yeah, I just had to shit really bad."
Sam shrugged and walked back.
Lana noticed another feeling now. Like a feeling of an itch to scratch. They looked down and saw a bright yellow, protruding member from their genitalia. "What the fuck." Lana groaned. "Knew I should've been more cautious with that unknown specimen."
They started to poke the member, and it responded by oozing pink fluid, almost like pre-cum in consistency.
"This is even more embarrassing than I thought," Lana was thinking.
Lana zipped up their clothes, despite the pain of this new engorged member feeling so confined, and went back out and sat down again. Lana continued reading, trying to pretend that nothing had happened.
Thankfully, Georgie and Sam were now asleep in the bunk beds.
Lana felt an overwhelming urge to fuck. "Okay, maybe if I just sleep," they thought, and then laid in their bed. Their bed was near Georgie and Sam's beds, so it was really hard to suppress the urge to grab one of them and...
"Why am I like this? I have never felt so rapey before," Lana thought.
Lana really couldn't sleep. The sexual urges kept growing as they freed their new member and stroked it. It had grown by at least 7 inches.