As romances flower into long-term relationships, the sex commonly, cruelly, wilts. If once you couldn't get through dinner without a hurried tryst in the restaurant bathroom, now a few weeks, a few months, maybe even a year can pass without a roll in the hay, or at least without one worth remembering.
That's fine if both partners are happy with the new order of things. More often, however, vanishing sex lives cause couples distress.
"It's not just about different sex drives, but a complete lack of empathy about being in the other person's shoes," said marriage therapist Michele Weiner-Davis, author of The Sex-Starved Marriage: A Couple's Guide to Boosting Their Marriage Libido (Simon & Schuster) and founder of divorcebusting.com. "That sort of breakdown can put marriages at risk for infidelity and divorce."
Couples could save themselves grief if they discuss expectations for sex as they plan their lives together, just as they discuss values around children and finances. But people mistakenly believe sex is something that should naturally fall into place, Weiner-Davis said.
Multiple factors conspire to diminish a couple's sex life once the idealized halo of new love fades away: a partner's annoying habits, job stress, babies, relationship strife, life trauma, depression, aging bodies, boredom with the same old sexual routine.
There's a natural ebb and flow to any sexual relationship, so a dry spell doesn't have to be a crisis, especially if you can chalk it up to acute stress or a busy travel schedule, said Dr. Virginia Sadock, director of the human sexuality training program at New York University Langone Medical Center.
But if those dry spells happen with some frequency, she said, it's time to pay attention.
Sex is physically healthy and emotionally bonding, and it helps to grease the wheels of the relationship when life gets tough, Sadock said.
There is no prescription for an ideal amount of sex, but it's a primal need, "so if you're having sex less than every couple of weeks or a month, probably something's up," said Dr. Gail Saltz, a psychiatrist and author of The Ripple Effect: How Better Sex Can Lead to a Better Life (Rodale). (The average rate of intercourse for married couples is 1.7 times weekly, but there's wide variability among ages and individual couples, and experts say every couple should decide what's best for them.)
For many people, sex is a way to feel close, connected and desirable, so going without feels especially hurtful, Saltz said. It can be hard for the lower-desire partner to understand that need — just as it can be hard for the higher-desire partner to understand that less sex doesn't necessarily mean less love.
Partners dig in their heels at their peril.
Sex, Saltz said, "can be a testing ground of what you and your partner can compromise on."