Mother & son have to breed or die

Cory and her son have been by aliens and placed in a habitat to be observed. The aliens wish to study the mating habits of humans and command them to breed. They try to explain that family members don't have sex, but the aliens don't care. "breed or die" they announce. The son tells them to fuck off and gets painfully zapped for his reluctance. Cory wakes up her son and explains to him that they don't have a choice.