Yep! Time to break that in!

"Alright Megumin," Kazuma started, making Megumin pause and glance at him. "I'm going to want you to relax, okay?"

"Alright, should I keep eating Darkness out? I don't think she came yet... Odd," Megumin noted.

"Sure thing," Kazuma grinned as he knelt behind Megumin as she started fingering Darkness.

"Going to fuck me from behind again?" Megumin asked him with a smile.

"Yes and no," he smirked.

She blinked. "What does that meEEAAAN!?" she yelped as he pushed forward a bit, pressing the tip of his cock into her anus. She took a second to recover from the surprise, before she looked back and giggled. "Oh, I see. Okay then!"

She then resumed licking Darkness's pussy as Kazuma slowly pressed further into her, eliciting several moans from her as he did. He soon buried his cock to the hilt in her ass as she gasped a couple of times into Darkness's folds.

Darkness giggled. "Intense, isn't it?" she teased Megumin as Kazuma slowly withdrew and pushed back in.

"Y-yeah... Why aren't you cumming yet?" she then asked, confused as she fervently fingered Darkness's quim, even tweaking her clitoris a bit. "Are you even feeling this?" she asked, just a bit frustrated, before moaning out again as Kazuma started to speed up.

"Maybe. Keep trying!" Darkness giggled as Megumin kept licking and fingering, going at it more and more intensely, partly taking it as a challenge, partly out of pleasure she was getting from Kazuma fucking her back door.

He sped up even more, groping her ass as he kept going. "Oh! Unh!" Megumin jerked with every thrust, gritting her teeth at the overwhelming feeling he was giving her. Several minutes in, he was pounding her at top speed, his pelvis slapping against her ass until his cock started throbbing.

"I'm gonna cum!" he gasped.

"Me too Master, fill me!" Megumin begged, before crying out in sheer delight as she came, feeling his seed flooding into her rear. She collapsed as he pulled out, grinning, but she was still fingering Darkness almost absentmindedly now.