Worries about AI often imagine doomsday scenarios where systems escape control or even understanding. But there are nearer-term harms we should take seriously: that AI could jeopardize public discourse; cement biases in loan decisions, judging or hiring; or disrupt creative industries. However, we foresee a different, but no less urgent, class of risks: those stemming from relationships with nonhuman agents. AI companionship is no longer theoretical--our analysis of a million ChatGPT interaction logs reveals that the second most popular use of AI is sexual role-playing. We are already starting to invite AIs into our lives as friends, lovers, mentors, therapists, and teachers.