In the mouth

She slides off your dick, hesitantly, almost like she didn't want to, but had to. She took a knee in front of you and engulfed your cock in one quick move. Her face bobbed back and forth slowly, then quickly, then too fast to deny. You fire off a massive load in her mouth, and she sucks down every drop like cool water. And you give her a lot to drink. For a full minute you squirt shot after shot of cum down her throat, and even when you stop, she keeps sucking, hoping there's more to be had. When she realizes there is none left, she smiles at you, dresses herself and vanishes into the shadows.

You may be stuck mysteriously in a world that shouldn't exist, but you can't help smiling as you realize what you've just done. You made a ninja a cum-slut.