He'd done the minimum expected. Now he could truly go all out and he did just that bringing himself close to that cliffedge of pleasure around the same time Lucy gave him that needy warning. He heard her words, registered them in his mind however he did nothing to stop. Why would he when the peak was something they could both share.

"Do it. Let it go!" Natsu grunted, urgency and passion filling his voice as he bounced Lucy in his lap even more vigorously.