What happens to sex in long-term relationships over time? In long-term relationships, the amount and strength of sexual activity usually decreases over time. This is called the "sexual desire discrepancy" and happens to many couples. There are many reasons for this, such as the excitement of a new relationship wearing off, stress and tiredness making it hard to prioritize sex, and getting used to each other's company. However, not all couples experience this decrease in sexual activity. Some couples maintain their sexual connection by being open and creative about what they want. Others find that sex becomes less important but still maintain their emotional and physical closeness in other ways. Although the amount and intensity of sex may change in long-term relationships, it's possible for couples to have a healthy and satisfying sexual connection by being open to new experiences, communicating with each other, and adapting to changes over time.