Lewd Sibling Duo Version 3.1 by Mike Meier

Overview:
LSD features two main protagonists, brother - a prominent young biologist, and his older sister - a college professor. On a quest to rid the population of a terrible infertility plague that threatens the very existence of humanity, they discover that their solution has some interesting side effects on women.
Lewd Sibling Duo Version 3.1 by Mike MeierLewd Sibling Duo Version 3.1 by Mike MeierLewd Sibling Duo Version 3.1 by Mike Meier