When Ben Tennyson found out he was going to be spending his summer vacation traveling around in an RV with his grandpa and annoying cousin Gwen, he thought he was in for a very boring, very long summer from Hell. Amazing how things change after you find an alien watch that turns you into a number of different weird heroes from outer space. The Omnitrix could transform Ben into a variety of different aliens, but after toying around with it, he discovered some other tricks it had. Gwen had scolded him for messing with it, but who was the dweeb now that Ben had the power to shrink himself and others with the cool alien watch.
Right now, Ben was suppressing the urge to laugh as he remained as quiet and still as possible as he prepared for another prank on Gwen. He had woken up early, which was hard for him, and snuck into her room, shrinking down and finding the perfect place to hide to give her the proper wake-up call when she finds him. His hiding spot: Gwen’s panties.
He waited and listened as she got up, strutting around her room naked as she got dressed while still half asleep. She slept nude, a fact that Ben knew all too well. Biting his lip in anticipation, he saw two massive feet come down through the sides of the panties before he was pulled up. Ben stared up, getting a good look at the smooth, soft pussy and round, soft ass of the young redhead, a sight he wouldn’t mind looking at a bit longer. Too bad, Gwen pulled him up a second later, cramming him right into her hairless mounds. Ben breathed in her aroma and then started to move, shifting against the opening as though to arouse it. Instead of moans, he got a scream as Gwen suddenly found something nuzzling her crotch.
“You little pervert!” Gwen fished her cousin out of her panties, seeing him smiling innocently at her as she glared angrily at his puny face. To say their relationship was an odd one would be an understatement. Always arguing, pranking, teasing, and fighting with each other, yet they both had needs that the other was very good at taking care of. Gwen found her tiny cousin to be the perfect sex toy, great for messing around with and enjoying herself. Ben found the giant cousin attractive and kinky enough to let him do things he could only dream of. They both claimed it was just circumstances that brought them together, that what they did meant nothing, but something was growing between them as they repeatedly crossed the line.
“What did I tell you about going into my panties?” Gwen hissed, squeezing the tiny boy as she glared at him. She was only in her panties, leaving her flat chest exposed, not that she cared. They had seen each other up close and personal too often to get embarrassed by the other's body.
“That I can only go inside with your permission,” Ben responded in a petulant tone. Gwen nodded, not liking when Ben acted without her giving him orders. She liked being the one in control, even though she was often left a panting, limp mess at the diligent squirming of her little sex toy. She thought she was the boss, while Ben thought he was the one really in control. He looked at her now, a smile on his face. “So, can I get back in your panties and finish what I started? Come on, you know you want it.”
Gwen frowned; she did want it. Just seeing how small Ben was and holding him in her hand was getting her aroused. Her body craved him, but her pride came first. “Take a cold shower, pervo.”
Gwen tossed Ben on her bed and started getting dressed, not bothering to look at the puny boy. Ben fumed, annoyed at being denied, especially because he was rock hard right now. Before he could call out to Gwen to come back, she finished dressing and left, leaving him alone with his erection. Grumbling, he looked at the Omnitrix, which was glowing blue. It always did that when he was small. Slapping down on it he returned to normal size in a flash. Back to regular size, Ben still looked at his watch, wondering if he could try to convince Gwen to try shrinking next time. The watch, when properly set, could either shrink him down or shoot out a beam that shrunk other people. He had hit Gwen with it once and got yelled at by the shrunken girl until he returned her to normal size. A little role reversal with Gwen sounded fun, but she liked having him under him, literally. Not that Ben was complaining. He loved the kinky ways Gwen used him.
“Call me a pervert? You’re the pervert,” Ben grumbled as he met Gwen back at the RV as they started traveling again. The unconventional lovers refused to talk to each other at first, although their hormones drove them to glance at each other and fantasize. Eventually, they started talking again and things were back to normal. Gwen even planned to slip off with Ben for some fun once Grandpa Max was busy. That’s when they noticed that they were close to their next destination and peered out the window to see what was outside.