Gwen now lived in constant paranoia and worry of when Ben would grab her and lead her away from the RV for sex. He did so at least once now, and it had gotten to the point that she was actually relieved when he just wanted to fuck her, and spared her the pain of fucking her with one of his alien forms, as those were his nicest of days.
Today, Gwen realized, would not be one of his nice days. Be ordered her to undress as he decided at random which alien to use on her, eventually landing on Wildmutt, an alien she had been lucky enough to avoid being fucked by thus far. As Ben slammed down the watch, transforming into the large canine-like body, she realized that her luck had run out.
Ben knocked Gwen to the ground with his massive body, lining Wildmutt's large, thick canine-like cock up to her pussy. He held her arms down with his front paws and jerked his hips forward, thrusting his cock into her pussy with a groan of pleasure. Gwen grit her teeth, trying to be as quiet as possible so she wouldn't alert Grandpa Max of what was happening to her.
Ben bucked his hips hard against her, thrusting in harder and deeper each time, trying to hilt his massive, furry cock inside of her small, tight cunt. Gwen could feel his claws digging into her arms as he thrust harder into her, and whimpered when she looked down and saw her stomach bulging from the size of his cock fucking her. Wildmutt managed to hilt himself inside of her, bottoming out inside of her, making Gwen yelp as his tip slammed against her womb shortly before he came, filling her cunt with cum.
He pulled out, using his paws to roughly re-position Gwen onto her hands and feet. 'Doggy-style.' Gwen realized, mentally facepalming at the thought of hit. 'No,' She corrected herself as Ben used his paw to aggressive force her head down to the ground and raise her hips up higher, 'Submissive doggy-style,' she decided as she felt Ben line back up to her pussy and thrust into her pussy again.
Gwen was only able to last another few minutes before she started groaning in pain and shaking, her body quickly overwhelmed by the massive cock fucking her harder and deeper. Ben growled whenever she made a single movement that didn't follow what he wanted, and slammed his hips against hers harder as punishment, rooting his cock into her down the base.
Gwen cried out loudly when she felt Ben's cock start to swell up inside her, realizing that, whatever race Wildmutt was, his species really was remarkably similar to the canine's of earth, as they too forced their mates to take the knot. Ben let out a pleasured howling sound as he came, pumping several loads of hot cum into Gwen's tight pussy before finally pulling out and letting her drop, letting her think he was done with her for the moment, until he flipped her back over onto her back with his paws and lined his cock up to her mouth, jamming it into her throat, wondering if making her take the knot here as well would make her pass out, and deciding it would be good fun to find out now.
Ben had already fucked Gwen once for the day, making her ride his cock and suck him off in the bathroom of the RV first thing in the morning, and ordering her to jerk him off under the table during lunch. So, with at least a round and a half already under her belt for the day, Gwen had seriously thought that she was in the clear for the day. This was a bit too optimistic to be true it seemed.
Gwen realized this later that day when Ben took her a little ways away from the RV, stopping when they were obscured by several large rocks. Gwen didn't even need to be told what to do to know it was time for her to undress, and Ben smiled at this, choosing his alien and slamming the watch down, taking the form of Diamondhead as she finished removing her clothes.
Ben forced Gwen against a large flat stone, picking her up and holding her against it. Gwen grunted in pain from how roughly Diamondhead's solid fingers held around her as he held her hips in place and forced her legs apart. He lined up his impossibly hard crystalline cock up to her pussy, giving her just barely enough time to let out a whimper before he thrust forward, penetrating her with all nine inches of his stiff diamond cock.
Gwen cried out in pain, her legs locking around Ben's waist as he fucked her, ramming harder into her cunt harder to see how much of his crystal cock she could take. He thrust so hard into her that it made her bounce on his cock, her back hitting the stone she was against painfully as he railed her against it hard. Gwen held onto Ben tightly, not receiving any comfort from it, but was at least able to squeeze something with her hands to help keep herself from bursting into tears, which she did anyway a few minutes later.
Ben took multiple opportunities to smack Gwen's ass with his diamond hands, loving how she yelped in pain, enjoying how her pussy squeezed tighter around his cock and how red her ass turned after just a few strikes. All of these factors just led Ben to rail her harder against the stone. After a few more minutes, Ben wasn't even holding her up, placing both hands on the stone above her head and just slamming his hips forward, having hilted his cock inside of Gwen's pussy and wanted to see if he could actually crack the stone from how hard he fucked her before he came.
As it turned out, no, he could not, but releasing his thick seed inside of Gwen and hearing her cry out in agony from it was still just as satisfying. He pulled out of her, letting her drop down onto her knees in front of him. She squeaked in surprise as he grabbed her and thrust his cock down her throat, but she wasn't really surprised until a few minutes into it, when she had started deep-throating him, only to gag when she realized that he could increase the size of his stone cock inside of her and slam against the back of her throat.
And she was even more surprised when Ben used Diamondhead's power to summon crystal to rise to thick, hard rods of the gemstone underneath her to penetrate her ass and pussy as she sucked him off, making her groan and whimper around his cock as they raised higher, probing deeper into both of Gwen's holes, sending pleasurable vibrations through his cock.