Both.

Natsu gave her ass another slap, and lined his dick up with her cunt as she moaned. Lucy bucked her hips into Virgo's mouth and spread her legs further apart to give her easier access.

Natsu then slowly pressed into Virgo, parting her folds with his cock, and making her moan into Lucy's folds. He bottomed out and settled for a few seconds. Then, gripping Virgo's ass, he started to slowly glide his dick in and out of her.

Virgo tightened her grip on Lucy's thighs a little bit, and cooed as she kept on licking at Lucy's pussy. Lucy gasped as Virgo's tongue went over her clit, and she put her hands on Virgo's head to draw her in a little more.

Natsu then slapped Virgo's ass once more, getting a slightly surprised yelp of pleasure from her, as she hadn't expected him to continue doing that while fucking her. She crooned a bit, losing herself in it as her tongue worked more furiously, her body jerking slightly as he struck her rear again.

"Mmm!" she squealed as he started to pound into her. Lucy pulled her head back in and arched her back as she felt Virgo return to licking her, sliding her tongue into Lucy's entrance.

"Ah, Virgo..." Lucy sighed happily, still blushing, but really enjoying it as she felt her pussy start to twitch. She then screamed out as she threw her head back from the orgasm that tore through her body.

Natsu didn't last much longer after that, and let his seed loose as it flowed into Virgo's snatch, which clamped down as the blushing Celestial Spirit bit down on her knuckles to muffle her own cries of pleasure.

"You can stop licking Lucy now," Natsu panted as he pulled out of Virgo, giving her pinkened ass a final smack. Virgo nodded and let herself collapse a little, a contented smile on her face, matched by Lucy's.