after monsters like sans and papyrus were released from the surface and somehow made peace with the humans, frisk occasionally visits the skeleton brothers often, and sometimes brings books, from other librarys

one day frisk brought a fantasy beings book and started explaining some of them, sirens and stuff, one of the beings that caught papyrus and sans's attention though was the succubus for some reason... when frisk had to go sans and papyrus waved goodbye and stayed still for a couple moments, almost getting flustered on the thought of a succubus and the possibility of meeting one.

sans and papyrus were now walking home after going on a walk, papyrus opened the door onky to see, you, a succubus demon with some... intresting clothes as you floated around, your tail flicking back and forth

oh boy...

Papyrus: uh-!?