He decides to return the previous favor.

"... hold on a second Momo," Izuku said, blushing slightly as he thought about something. He was getting used to having her as her all too willing sex ****, albeit slowly, and decided what he wanted to do next. "Sit on the edge of the bed, and spread your legs for me."

Momo brightened up, the order delighting her. While taking some initiative to please him had its charm, her genie nature favored receiving direct orders. And he was starting to get a little more assertive. She didn't think he was about to fuck her, mind you, but she'd gladly settle for just letting him see her pussy for now. "Yes Master!" she nodded, excited as she seated herself on the edge of the bed and parted her thighs, putting her snatch on display for him.

Izuku gazed at it, his heart pounding. He had gotten a few good glimpses of it in her nude state already, but this was his first unobstructed, uninterrupted look. Her folds were glistening, and so inviting, he could stare at it forever. But, he had other matters with it to attend to. "Stay still," he told her, trying to sound firm as he approached.

Then, to Momo's surprise, he dropped onto his knees and reached forward a bit hesitantly, and began tracing her folds and her mons with a finger. "Oh... You want to touch it too, Master?" she crooned, squirming slightly, but otherwise obeying his order to stay in place.

"...more than that," he replied, nervous, but set on his current course of action. He leaned forward, and extended his tongue, licking her entrance.

"Ah! Master, what are you doing?" Momo gasped, though she couldn't say she didn't like it.

"I'm returning the favor for the blowjob from earlier," Izuku answered, before resuming his tentative licks.

"Ah, oh... You don't have to, I really did enjoy doing it," Momo replied.

"But I want to. So just relax and let me give you pleasure freely," Izuku stated with a smile before getting back to it.

Momo obliged, relaxing as he had gently but firmly commanded. She let him continue, her heart racing, her face full of eagerness at receiving cunnilingus from her Master. She had momentarily been concerned about the dynamic of this, as she wanted to be the submissive one, but no, this wasn't about her Master submitting to her. He was still very much in charge. He was doing it of his own accord, not out of obligation. She once again felt like she had hit the jackpot as far as Masters went.

Izuku continued his attentions, sliding his tongue into her entrance, and working it around. He was pleasantly surprised by the flavor of it. He was expecting something more salty or acidic, but it tasted sweet, almost fruity, though he couldn't place what fruit it most resembled. He supposed this was because she was a genie. Regardless, he kept going, caressing her pubic mound with his fingers, appreciating the smooth feel.

His attentions were a bit on the clumsy side, his inexperience on display, but he made up for it with vigorous enthusiasm, and attentiveness, observing her responses closely to determine what got the best results regarding her pleasure. Turned out, his ability to analyze things applied to more than just Quirks. Who knew? As such, his learning curve proved pretty steep.

Eventually, his focus shifted to her clitoris. The cute, hypersensitive little nub captured his interest as he withdrew his tongue from her folds, replacing it with three fingers. "Oh!" Momo gasped as Izuku did this, followed by starting to lick her happy button. "Yes, please, Master, more!"

Izuku didn't need telling twice, growing more and more confident with each lick, and working his fingers in and out of her and going at it vigorously. Momo kept squirming as much as she felt was allowed, given his order to stay still. She refrained from bucking her hips as she rapidly approached her release. "Master... I'm almost there..." Those words spurred Izuku on, and he redoubled her efforts. "Unh!" Momo moaned, doing her damnedest to keep it quiet, biting her lip and leaning her head back as her orgasm hit her. Her pussy lips spasmed around his fingers, her clit twitching.

Izuku pulled back and smiled at her. "Did you enjoy that, Momo?"

"Yes, Master, I did. Though to be honest, I preferred giving you head," Momo panted.

"Really? Was I that bad?" Izuku asked, pouting.

"Not at all!" Momo replied with a serene smile. "It was definitely good, enjoyable, especially for a beginner. It's just how I'm wired as a genie."

"Oh, right," Izuku chuckled sheepishly. Momo giggled a bit.

"I still liked it though," she reassured him, getting up and hugging him. He froze up briefly, before returning it.