Looking for a manga

Im looking for a manga and the plot that i remember is as follows. A boy is living with a relative that shows him off to others sexually. There is a doll that looks just like the relative and he has sex with the doll because it reminds him of his relative. The relative is his cousin i think and the cousin misunderstands that the boy is in love with the dolls original owner. there is also milk and cansy involved in the sexual escapades. Thank you in advance for your cooperation.