Interestingly.

"So how does Charm work?" Tsukane asked curiously, as he began to thrust his dick between her bosom.

"Well, as you probably guessed, it needs eye contact, but it works on anyone of the opposite sex," Kurumu moaned as Moka licked at her pussy. "I can essentially control their actions through it. Can't use it on females though, only the Incubi could do that."

"Could?" Tsukane asked as he continued to thrust into her tits.

It took Kurumu a moment to answer, as she gasped out while Moka's tongue hit a sweet spot. "...they may have gone extinct, but no one knows for sure..." she panted out, before biting her lip as Moka really got into it. She leaned forward and gave his tip a quick lick.

Tsukane groaned in pleasure as well while he groped Kurumu's chest. "Aren't Succubi and Incubi the same species though, just different genders?" he then asked curiously.

"More like cousins," she crooned. "But while they used to be able to interbreed if they were fated for each other, the downfall of both monster types was that they can only have children with their fated ones... And should a Succubi have a male child, it will always be the same species as the father, only the girls are Succubi... The same was true of the Incubi, only inverted. That led to the Incubi and Succubi being **** to extinction. The difference is that Succubi were more willing to look for their fated encounter, while Incubi... Just tended to prefer to screw any girl they could get their hands on, whether it could bear children or not."

"Thus, they either died out, or ultimately went into even deeper hiding than most other monsters," Tsukane realized as he felt his cock throbbing, even as Kurumu sucked on his tip.

"Indeed," she cooed, giving it another lick as she did so. She then moaned out as Tsukane's seed burst out, hitting her tongue and face. She then shuddered as Moka successfully brought her off, and her back arched as a result, shifting Tsukane slightly, and he got off of her.

"It's more likely they died out in my opinion," Moka noted as she licked her lips. "If there were still Incubi about, they would have had some more trouble hiding among both humans and monsters with the fact that they'd have to actively seek out their mates. That's just my thoughts though."

Tsukane nodded in agreement with the logic even as he tried to catch his breath.