This is my first Ben 10 fanfic and this is about Gwen Tennyson and a mysterious person who she's having a relationship with. What if Ben and Kevin find out? Will this secret affect the team and the future of their teamwork. Based around Ultimate Alien and there will be aliens showing up. Find out now!

Hope you enjoy.

Mr Smoothie's:

After a tiresome day of fighting Forever Knights and training, the three Plumbers were drinking smoothies and laughing. Ben and Kevin started talking about their cars while Gwen went to get some more smoothies when she heard her phone vibrate, she took her phone out and saw she had a text message.

"Can we meet at the lake?" The person asked and Gwen smiled as now she was looking forward to seeing her secret friend so Gwen sent a reply.

"Sure, see you at 7 tonight." Gwen placed her phone back inside her handbag and collected the smoothies then walked over to Ben and Kevin, Ben was on the phone to someone while Kevin was checking his engine.

"Who's Ben on the phone to?" Gwen asked and Kevin shrugged his shoulders as he didn't know who the caller was.

"I don't know. Me and Ben were talking what aliens he has in the Ultimatrix then all of a sudden, he gets a phone call and look at him," Kevin told Gwen and they both looked at Ben who looked very cheerful. "But whoever it is, he's seems really happy about it." The pair nodded then started drinking the smoothies.

"Sorry about that guys, that was Julie," Ben told them as he stuck his phone back in his pocket. "She's just returned from a tennis match and wants to go out for dinner." Ben took his smoothie and started drinking it, Gwen smiled at the fact of her going out to dinner with her mystery friend.

"Well, I got to go. I got some studying to do in case we need some new spells." Gwen told the pair nodded then Ben and Gwen walked over to the Mark 10 and drove off, leaving Kevin to upgrade his car with some more power to the engine and brakes, plus the weapons.

Gwen's house:

The Mark 10 arrived at Gwen's house, the passenger door opened and out stepped Gwen and she was smiling as her phone just beeped again. Ben looked over and at his cousin and noticed at Gwen was checking her phone.

"You okay,cous?" Ben asked but Gwen was too busy sending a reply back to the mystery contact. "Gwen?" Ben was curious about who Gwen was talking to.

"Yeah? Sorry Ben," Gwen apologized then stuck her phone back inside her handbag before turning back to Ben. "It was a friend, she wanted to know if I could help her tomorrow." Gwen told her cousin then she waved goodbye and entered the house. It didn't take long for Gwen to walk upstairs and look out her window to see that Ben had drove off so he could meet up with Julie. Gwen took out her phone and went straight to her mystery contact's number and pressed dial and the caller answered it very quickly.

"You called?" Asked the other person and the voice made Gwen smile, her smile was even bigger than the one he had when she passed her driving test.

"Yeah, I'll be there soon. Love you." Gwen told her caller which made the person smile on the other end then the call ended. Gwen decided to use the powers to fly herself to the location to avoid being seen.

Ben's house:

On the couch, Ben and Julie were passionately kissing each other as Julie had been on the other side of the world in a tennis tournament. They were about to get further into their fun when the front door opened and in walked Kevin, his hands and face covered in oil and dirt from working on his car.

"Hey, Ben…" Kevin stopped talking as he saw Ben and Julie laying down on the sofa kissing until, they jumped up to reveal that Ben's was minus his green jacket and Julie's white vest had been lifted to reveal her stomach. "That's something I can never unsee." Kevin walked off in the direction of the bathroom so he could wash his hands while Ben and Julie got their clothes off the floor and looked into each other's eyes.

"Should we finish this another time, Ben?" Julie suggested, Ben blushed and nodded then the pair kissed each other. Ben watched as Julie got her jacket and shoes on then left the house.

"See you later, Julie." Ben called out then watched her walk down the street as he put back on his jacket and walked back into living room to see Kevin walking in with two sodas.

"Sorry about that, dude," Kevin apologized as he gave a soda to Ben who nodded. "I came to tell you that I found some Knights buying some new alien tech and found the looks of it, they look like the type of weapons that a Galvanic Mechamorph could create." Ben nodded and Kevin smiled, the two decided to go and deal with the Knights and the dealer.

Meanwhile:

By a lake, Gwen had arrived and was still wearing her usual clothes, she was looking around to see if her friend had arrived but she hadn't. Gwen walked over to the edge of the lake and sat on a rock, she was staring at the water but didn't hear the phone ringing as she turned around to see her friend had arrived.

Abandoned warehouse:

It was quiet in the warehouse district until the sounds of screaming in pain were heard. Inside the building, the Knights were trying to fight Kevin who had absorbed the metal from one of their armors while Ben had transformed into Four Arms, the pair were hitting and tossing the Knights in every direction.

"Hey Ben!" Shouted Kevin as threw two Knights and Ben smacked them out via the roof. "This is going to get interesting now!" Kevin pointed at the three walking tanks coming their way.

"Let's try something quick then," Four Arms suggested then he hit the Ultimatrix and changed into Diamondhead. "I'll hold them in place and you cut them down." He suggested and Kevin nodded. Diamondhead raised both his arms and out of the ground came giant diamond shaped hands, they grabbed the tanks so that they were now stuck which gave Kevin the chance to cut the legs and the top of the tanks to fall to the ground.

"Nice idea, usually that's Gwen area." Kevin told him and Diamondhead and nodded then they looked around the warehouse. "Something wrong?" Kevin asked as his armor melted away and Ben changed back to normal.

"Yeah, where is Gwen?" Ben asked and that got Kevin's attention so he told out his Plumber's badge and decided to check her location. "Found her? I'm just worried because she's always here with us kicking butt and also telling you what to do." Ben joked on the last part which made Kevin looked at him with a stern face.

"According to her badge, Gwen's at her house." Kevin told Ben then after they sorted that out, the two decided to look around for anything to track down the Knights.

At the lake:

There was a picnic basket laid out on the grass and there were two female figures enjoying themselves with drinking champagne and laughing, one of the females had redhead and the one had silver hair and a black head crest.

"I love spending time with you," The redhead flirted with the silver haired and she two moved out of the shadows to reveal themselves as Gwen Tennyson and Charmcaster. "Who would believe me that I'm dating and in love with you?" Gwen asked which made Charmcaster smile.

"Come here, Gwenny," Hope seduced as she removed her head crest, Gwen moved close to her secret girlfriend and the two started to passionately each other. "Shall we go somewhere more private?" Hope suggested and Gwen nodded, a huge magical door appeared and opened to reveal the Charmcaster's bedchamber in Ledgerdomain, the two walked through the door and as it closed, the pair got back to kissing each other and enjoying each other's company.

Meanwhile:

Kevin was at the garage trying to figure out where the weapons came from until his research came to a halt when he heard a car pull up outside, Kev went outside to see Ben get out of the Mark 10 then tossed over a Plumber's badge.

"That's Gwen's, she's not at home and when I called her cell, it went straight to answerphone." Ben told Kevin which made the two wonder where Gwen is.

"Let's go and look for her, she may need us." Kevin suggested so they both got into their cars then drove off to search the city and the outskirts but they didn't know that Gwen was in Ledgerdomain with her secret girlfriend, Charmcaster.

That is chapter one finished, I hope this starter was good as like I like said, this is my first Ben 10 fanfic and I thought about writing a Gwen X Charmcaster one as I liked the pair. Chapter 2 should be done soon so don't rush me.

Please review this so it can help me improve for the future.