Tomodachi ga Urayamu H Sugiru Boku no Mama to Onee-chan wa,Tokoro Kamawazu Boku wo Yuuwaku wo Shite Kimasu.

My new stepmom and stepsis, through a custom from the countryside that they grew up with, both believe that a younger brother's sexual relief is their duty... Even at school, in the classroom; Even at my mother's part-time workplace; Of course, even at home. They will seduce me, no matter where. (Source: DLsite, translated)