We examine the relationship between sexual activities and happiness using a sample of 3800 adults from China. We provide some results about the relationship between sexual activities and happiness for an important country other than the United States. We find that those who have more sex and better quality sex, proxied by emotional and physical satisfaction with one s primary sex partner, are happier. We find that the happiness maximizing number of sexual partners is one and that engaging in extramarital sex is negatively related to happiness. A third important finding is that having unwanted sex is associated with lower happiness for both men and women.