Almost immediately! After a quick bit of fun with Akemi!

"Hey, Momo, Akemi, you guys in?" Denki asked, arriving at his place, not worried about whether his dad was home. He had already wished for their respective families to be aware of and accepting of them all being in a relationship, even though said families weren't away of the Sex Genie details. That of course was Momo's idea.

Akemi, hanging out in the living room, looked up. "Sorry Master, Momo's still taking the test for Reccomendation students. From what she said, it's both easier and harder, easier because there is a smaller ratio of contestants to openings, but harder because the material is more... extensive..."

"Oh, I see... so she'll be a little bit longer then?" Denki nodded in understanding.

"Yep... guess we'll just have to pass the time ourselves, won't we, Master?" Akemi asked him mischievously.

"I couldn't agree more," he smiled, undoing his pants.

...

About thirty minutes later, Momo arrived. "I'm back!" she announced, heading for the bedroom. She walked to the door, and heard the sounds of obvious moans and fucking going on in there. With a smirk, she opened the door, and was treated to the sight of Denki fucking Akemi Doggy Style. "...couldn't wait for your poor genie, Master?" Momo inquired, teasing him.

"Unh..." Denki moaned, before looking towards her, and grinning, not slowing his thrusts into the squealing Akemi in the slightest. "You say that like you actually mind me having a bit of fun..."

Momo giggled at that. "Of course I don't, I'm just teasing..." she replied, starting to strip down. "How was your test? Meet any cute girls?" she then questioned.

Denki grunted, and soon came inside of Akemi. Akemi gave another moan as she also came. "As a matter of fact, I did," he panted, pulling out of Akemi. "And I definitely want to add her to the harem. Especially if she enjoys it as much as Akemi does..."