Make her pleasure both of them!

"Okay, Master, if I might have permission to have my cunny in tail form, and choose the position?" Lucy cooed at Natsu, placing a hand on Virgo's cheek.

"Granted," Natsu nodded. "She's your spirit after all." Immediately, Lucy's legs dissolved into the purple mist again, and connected to where he had the lamp spout. Lucy then proceeded to wrap her tail around Virgo's wrists and neck, positioning her misty appendage where her pelvis would be as the mist reshaped into a vaginal opening. She then sat herself on the floor, pulling Virgo onto a kneeling position, where her ass was presented to Natsu.

"Oh... Mistress..." Virgo blushed as Natsu knelt behind her, surprised at how solid the vapor could be when Lucy wanted it to be.

Lucy beamed as she leaned back on her hands. "You know what to do," she purred as Virgo yelped and jolted in pleasure from Natsu entering her passage from behind. After taking a moment to compose herself, Virgo leaned forward, and started to lick the outer folds of the vapor forming the vagina. Lucy crooned and wriggled her gaseous hips. "Oh yes, like that!"

Natsu chuckled, resting his hands atop Virgo's ass, and he began to move, gently thrusting his hips back and forth in her. "Mmmph!" Virgo moaned into Lucy's snatch, but didn't stop licking.

"Wow... Her pussy sure feels great..." Natsu moaned as he kept going, pumping his hips hard and fast into the Celestial Spirit. "Soft and tight..."

"I know... And her tongue is pretty skilled... She deliberately moves it like she's inexperienced, but talented, the right mix of tentativeness and enthusiasm," Lucy crooned as she writhed her "hips." "Keeps the theme strong..."

Virgo could only give another muffled moan into Lucy's cunt. She tightened her vaginal walls around Natsu's manhood. If Lucy hadn't bound her arms in that genie tail, she would be adding some fingers to the fun. "For someone called the Virgin, you're quite the slut!" Natsu grinned as he upped the intensity.

Virgo shivered in arousal at his words, her submissive nature relishing the statement. She inserted her tongue fully into Lucy, wriggling it about, trying desperately to elicit more pleasure from her Mistress. "Oh, good girl, keep it up, I'm close!" Lucy gasped as she bucked her lower half into Virgo's face again.

"So am I!" Natsu grunted, pounding her as his member pulsated.

"Mmmnh!" Virgo moaned, her pussy spasming and getting Natsu to erupt inside her, before Lucy also cried out, orgasming hard. Virgo's own climax also claimed her slender body, and she would have collapsed if she was not held up by Natsu and Lucy.

They all caught their breaths, basking in the post orgasmic bliss.