Akuma no oshigoto [studioGGB]

-You hear rumor of a book that gets delivered in the mail.
A book from which demon girls appear to fulfill certain needs.

Not entirely convinced of the validity of this story… one such book is delivered to you.
You pick up the book and…

Two demon girls suddenly appear before you and help you fap for a good 28 minutes!
Ready for a full course of sexy fellatio, irrumatio, missionary, cowgirl style, creampie and cum guzzling!?