Next morning

The next morning you wake up to the smell of Sarah cooking up breakfast. As you blink, you see that Karen is still out cold. You and the other two guys head into kitchen to find Sarah who says "Hey guys."

"Hey." Matt says.

"So what the hell happened last night?" Tom asks.

Sarah shrugs. "Nympholunamorphic transformation."

"What?"

"She becomes insatiably horny on a full moon about every two months."

"How do you know all this?" You ask.

"You know my last name isn't actually Singer."

"It isn't?"

"Van Helsing."

"Like the monster hunter?"

"Yep. I'm a direct descendant."

"So you know about all this?"

"Yeah. It's been around for around a millennia, but most women just killed themselves out of shame. Whilst no known cure, with the invention of the vibrator, most women struck with this curse were able to be added. At least for a while, anyway. I mean that or they can just-"

Tom grins. "So how does one contract Nympholunamorphic-ism?"

"No one really knows, to be honest.

That's when the woman of the hour enters the kitchen, looking to the naked group.

"Oh. So this is where I ended up." She says.

"You okay Karen?" Sarah asks.

"Yes my dear, thanks to you lot."

"No problem." Tom says.

"Y-yeah." Matt meekly adds.

"So glad you four could get control of me. I don't know what happened last night. Normally I have things under control."

"One step at a time." Sarah says.

"Right. Lucky Nicole has such good friends."

You raise an eyebrow. "Why?"

"Well, she's gonna need them once she loses her virginity."