"Phew took that one down quickly" said Ben 10 currently in Greymatter form
 Ben had just beaten down a monster and was a little tuckered out so he didn't bother changing back to human first. The RV rolled over to him and out stepped his cousin Gwen, a girl about the same age as him with short orange hair and a blue pin and she wore blue clothes as well. The two got into a fight before this so he wondered if she was still mad. Ben smiled still as Greymatter and waved at her. She glared at him before smirking.
 "You know I'm still mad" said Gwen
 "Yeah I kind of figured" said Ben
 "But if you do one thing for me then I'll forgive you" said Gwen
 Grandpa Max sighed still in the RV when he saw a store nearby and thought he could go shopping. He came out and looked at Gwen and Ben.
 "I'll go find some food and maybe some other things I'll be back in a couple hours" said Grandpa Max
 Gwen found the timing just too perfect as she looked down on Ben.
 "Just stay like that" said Gwen
 Gwen squatted down and lifted Greymatter Ben up who was wildly confused. Gwen giggled and opened her mouth which sent Ben into a state of panic. Gwen dropped him down into her mouth and closed her teeth sealing him inside. 
 "Gwen what the heck" said Ben
 Gwen licked the small body and swished the Greymatter Ben around her mouth making her cheeks puff out from side to side. She found him to be much tastier than she thought. Ben was panicking but figured it must be some joke and that she wasn't going to swallow. But Gwen had other plans and pushed Ben to her throat getting his feet inside her gullet. Ben screamed and held onto the slimy tongue and didn't slip down the slimy tube yet. Gwen giggled and walked into the RV and found a mirror. She looked into it and opened her mouth and could see Greymatter Ben clinging to her tongue.
 "Haha very funny let me out" said Ben
 Gwen shook her head and opened her throat up and watched as sheer terror overtook Ben's face as he slowly slipped down her throat. Ben's scream was cut off as he fully fell down into Gwen's gullet. Gwen shut her mouth and looked at the bulge in her throat and poked it, feeling Ben squirming.
*GULP*
Then with one single powerful gulp the bulge that screamed for dear life slid down past her chest. Gwen felt her small meal moving all the way down her gullet until he splashed into her stomach. 
 "For me to forgive you I want you to digest and become my shit" said Gwen
 Hearing that really terrified Ben since if he were to be digested that would be it for him.
 "C'mon you don't mean that" said Ben
 "Oh I do...digest Ben" said Gwen
 Ben was in a state of panic feeling Gwen moving around sloshing the pool of acid around. Gwen plopped herself down on the couch in the RV and poked at her flat belly giggling to herself. Ben knew if he stayed like this he was just going to drown so he had to do it. He has to burst out of Gwen's belly. Ben went ahead and turned back to a human. Gwen felt her stomach expand and watched as her shirt tore open and a massive belly came and sat in between her thighs.
*hhhurrropppppp*
Gwen belched loudly and laid her back against the couch and smirked, patting her belly.
 "I'm guessing you thought you could burst out of me...well looks like you can't your all mine Ben" said Gwen
 Ben didn't understand the walls only stretched to fit his form and now his human body was covered in stomach acids and he was incredibly cramped. Gwen rested on the couch as the weight inside her belly was too much to move. But he will be gone soon enough so she didn't fret.  
*bwarrrpppp*
She belched again with Ben squirming around inside her. Soft gurgles started to come from her belly as digestion was really taking a hold of the giant mass of boy meat inside her. She giggled poking at the bulge some more trying to rile her meal up to move more.
 "Struggle some more Ben it feels kinda good" said Gwen
 Ben didn't like that his moving was doing the opposite of what he was trying to achieve but there was no he was giving up yet. The green liquids were pouring inside filling the sack up. Ben felt his skin starting to burn a little and gulped nervously, refusing to accept the grim fate as his cousin's shit. But the more the acid burned he was starting to cry and even begged some.
 "Oh god please Gwen let me out it really hurts" begged Ben
 "Nuh uh..digest and become my fat" said Gwen
 Gwen laughed at Ben's pathetic begging and enjoyed all the movements in her stomach. 
*gurgle..glop..churn*
Ben looked down to see the acid had reached his crotch and it was burning through his clothes. His skin was turning a little red and Ben couldn't keep his cool any longer. Gwen all of sudden felt a sudden wave of wild thrashing and she smiled. Digestion was going full on against Ben's body and Gwen imagined it probably was incredibly painful. But she didn't care how badly it hurt; she wanted to see him as only a pile of scat. The screaming face and trembling hands that imprinted her gut made her giggle seeing the desperation across his body. 
 "Good be in pain...fear my stomach" said Gwen 
 Ben balled his eyes out feeling as his entire body was fire burning up as it slowly came apart. Ben couldn't fathom why Gwen would do such an awful thing to him and only encourage his death further. Gwen rubbed her squirming belly feeling Ben's movements getting weaker. Digestion seemed to be doing a fine job with her cousin meal. The stomach groaned loudly, pretty much blocking Ben's screaming. The hellish experience was getting worse as his clothes were torn to shreds and the mostly nude Ben was melting away. His body was all mushy looking as digestion did its work. 
 "No..n-ot like this" said Ben
 Ben felt his life fleeting away with his skin and body mixing I'm with the acid. Gwen had pretty much had her fun with Ben and was just patiently waiting for him to hurry up and finish digesting. Her belly was a bit deformed with the boy inside becoming mush. His movements were so weak she could barely even feel them.
*bwarp*
She belched and that was the last of the air inside her stomach. Ben passed out not able to breath and now his body was just a lifeless piece of meat in Gwen. Her stomach walls collapsed in on the boy snapping several bones and turning the once somewhat human form into a mangled mess. Gwen smiled seeing as her cousin was grinded up into a thick soup and her belly was rounding out. The bulges slowly shrunk down until only a soft belly laying on her thighs remained. 
 "Poor Ben all mushed up and just soup in his cousins belly...what a pathetic boy you were" said Gwen
 The answer she got back was a wet snap and a gurgle with her belly finishing off the meal inside. Bones started to appear pressing up against the stomach walls. A lifeless skull and rib cage imprinted the belly, making Gwen laugh. She was satisfied to see that her gut did a fine job on Ben and waited to absorb him. Soon enough all the mush started to push through her guts making her blush and moan. The soft belly was shrinking down as her thighs and ass grew some. Her assets grew as Ben became one with her in the way of fat. Gwen ended up with a big jiggly ass and thighs. She giggled finally able to stand up and slapped her booty making it jiggle.
 "What a pervy cousin going straight to my butt" said Gwen
 Gwen enjoyed shaking her ass seeing it jiggle around but a stomach groan and the need to shit hit her like a truck. So Gwen left the RV and walked a little bit away to some woodland area.
 "This seems like a safe spot to dump you" said Gwen
 Gwen pulled her pants and panties down letting her massive booty free and slapped it one last time seeing the bare flesh jiggle before squatting behind a bush. Gwen grunted and squeezed feeling as massive shit logs were pushing through her slimy bowels until they breached her asshole and started to slide out. Gwen moaned, feeling the soft poop smoothly slither out and coil on the ground. Ben was completely unrecognizable with only shards of bone and his brown hair stuffed into the shit. 
 "That's right come all out" said Gwen
 Gwen gripped her fat asscheeks and dumped massive shit with finger bones and teeth of Ben in them. White fabrics of his destroyed shirt were stained brown as the pile grew larger. Gwen was forced to stand as the pile was getting too big. The wet slapping of scat was music to her ears knowing Ben was just poop sliding out of her bowels. The omnitrix was wrapped around a log as she yelped in a little pain pushing the solid object out. Gwen didn't even realize it was there and immediately buried it in scat. 
*plap..plop..splapt..plap*
The shit rained from her booty and Gwen felt a little blockage. Gwen grunted and squeezed as hard as she could, feeling as her asshole slowly expanded open.
 "Ugh..come on..you little shit" said Gwen
 The white skull cracked and stained brown slowly made itself known until Gwen finally heard it pop out and fall onto the pile. The instant relief made her smile as the last few turds dropped off and splat on the lifeless skull. Gwen smiled and wiped using some leaves before pulling her pants and panties up. She turned to see the lifeless skull of Ben staring at her and laughed before waving and thinking of some excuse for Grandpa Max