Sue aimed the gun at Ben, setting it to "Genitals". She pulled the trigger.
Ben's manhood, previously a measly 5 inches, grew fast. Distracted by his sudden weight gain, he grabbed onto his dick, growing about an inch every five seconds. Soon, it was too big around for him to hold. His balls grew into large volley balls and his dick was around ten inches in diameter. His dick was around two feet long by the time Sue let go of the trigger.
She went back to the "Weight" option. She saw the minus sign, and shot the gun at Ben. He rapidly lost the weight. Once again, Sue was amazed, and only let go of the trigger when her brother was near anorexic.
Ben was dumbfounded. His sudden weight gain, massive dick growth, and extreme weight loss was very confusing. He decided it was all a dream, and shrugged.
Sue dropped the gun, and was touching herself. She stared at her brother, with his humongous penis and thought of a better idea.
She walked to where her brother was, and started feeling up his massive dick. Ben, convinced this was a dream, let her do it. He had always thought his younger sister very attractive— and if this was going to be a sexy dream, let be it.
Sue took off her pants and sat on his dick, which was now very hard. As it was now, it was two and a half feet long, and a foot in diameter. His balls were basketballs. Sue rubbed her wet womanhood all over his dick, them both moaning in unison.
Sue paused. She knew this was going to hurt. She got up slowly, grabbed the gun and turned it to minus and aimed it at his dick. It shrunk much smaller, foot long and five inches around. His balls still stayed the basketball size as Sue grabbed Ben's dick, and shoved it inside her.
They had rigorous, dirty sex with Ben breaking her hymen and thrusting deep, up to the hilt into her. Being inexperienced with sex, he came already and filled Sue up with his cum. Since his balls were huge, Sue's stomach bloated out a few inches from being filled. Ben pulled out of her, lied back, and fell asleep. Sue held her brother's juices inside of her, and came herself.
Sue was amazed at how great sex was. She stood, holding her crotch as to not lose the precious liquid and put her pants back on. She grabbed the gun and realized she knew someone that could help her with her sudden sex appeal. A friend and boy she liked, Shawn. She went over to his house and rung the doorbell.