Julie and her husband, John, have been together for 15 years. “At first, we were happy and had a great sex life. But after two kids, it feels like we’re just partners in raising them and accumulating what we want: a nice house, cars, vacations. It doesn’t feel like we’re romantic anymore. When we’re stressed, we take it out on each other, but save our best moods for our kids and friends. We can go days without touching, and weeks without sex. We love each other, but how can we get back to how we once felt?”

One of the biggest myths about marriage is that the thrill can’t last forever. It can last. We simply need to cultivate passion, just as we cultivate our skills in parenting and our careers. I’ve come up with a “Passion Prescription” that Julie and her husband can follow. Here’s what I advised for them for the first three weeks. But you can try it, too. Stick to it for at least three months to get the full benefits—and a revitalized relationship.