Just continue. With a bit of groping added.

"Oh, you really do feel good Levy," Natsu grinned as he ground his hips up a bit into her.

"Oh!" she gasped. "I thought I was doing all the work?" she whimpered.

"I can't help it, you make me want to help pleasure us a bit," Natsu grinned, taking his hands from beneath his head, and planting them on her waist.

"Unh... This is so dirty..." she moaned, leaning forward and planting her hands on his chest.

"Yes it is," Natsu agreed with a cheeky grin, sliding his hands up her sides.

"What are you... Oh!" she gasped out as he moved his hands over her tits and gave them a squeeze. Unconsciously, she pressed her chest into his eager hands.

"Your boobs feel great, I could grope them all day," he complimented her as she continued bouncing on his cock.

"Don't... Don't talk like that... I'm not that slutty," she whimpered, her pussy contradicting her by clamping down on his shaft at his words.

"No need to lie," he moaned. "I can tell you're enjoying this..." They got more frantic as their releases approached, Natsu's dick pulsing, before they both cried out and stiffened as Levy felt his seed fill her, and her orgasm passed through her intensely.

She collapsed on top of him as they panted, and Natsu turned to check the time, seeing it was late afternoon. Hmm... He could play with them some more... Or he could go back to his and Lucy's place, and play with her instead... He did want to be up bright and early tomorrow, as Erza had agreed to fight him then... Decisions, decisions...