Seems more sex doesnât equal more happiness âŠÂ A 40-year study of more than 30,000 Americans found that the happiest couples do it once a week. Researchers found that while couples who have sex once a week are happier than those who do it less often, having sex more than once a week âwas not associated with greater well-being.â According to the study, this was true regardless of gender, age, or how long a couple had been together. (The Frisky)