Fuck her.

He smiled as she continued to bob her head on his shaft with her hands rested on her knees. He pet her head as she looked up at him.

He then pulled back unexpectedly. "Master?" she whined.

"Yes?" Natsu teased.

"Am I doing a bad job? Did I displease you? If so, please punish me, I want to be a good slave for you..." she whimpered, unable to stand the thought of not being adequate in serving her owner.

"Nah, you haven't displeased me... I just want to change positions... Get on all fours and point your ass at me," he smirked.

"Oh... Yes, of course Master, thank you!" she gushed, immediately moving to comply, and shaking her ass at him. "I'm always ready Master, use me however you wish, I live to serve and obey you..." she cooed, looking back at him. "I love to be ordered..."

"Good slave," he told her, and she felt a wave of bliss wash over her as he said those two simple words. Hearing them meant she was pleasing her Master, which was her greatest joy in this state.

He knelt behind her, and she cooed, "My body is ready for you... It is your toy to enjoy as you please..." She then gasped out as his cock slid into her. She then focused on working her vaginal walls to let it slide in easily, then tightening them as he bottomed out to milk his cock.

"Ah... Wow, this is great..." Natsu moaned as he began to slowly fuck her. Erza simply cooed as she strained to focus through her own pleasure, on her utmost important task of bringing her Master off.