Not if your make the effort to keep it interesting. "Research shows that people married for a long time have the most frequent and satisfying sex lives of anyone—even the swinging singles," reports Parrott. That's because committed couples trust one another enough to express their deepest desires. Moreover, the emotional connection established over years allows for erotic levels of intimacy. Since sex is often as much about trust as it is about chemistry, long-term relationships offer the possibility of a high-quality (and high-quantity) sex life.