Most of us just accept that relationships lose spark over time. Intensity fades, the butterflies settle, and eventually you slide into something steady, comfortable, and routine.
That seemingly unromantic shift towards feeling more like roommates than crushes isn’t inherently bad. In fact, “if you go into any relationship thinking it’s going to be the honeymoon stage forever, you’ll be sorely disappointed,” Erika Ettin, MBA, a New York City–based dating coach and founder of A Little Nudge, an online dating consultancy company, tells SELF. In some cases, however, there’s more to a creeping sense of boredom than just stability.
Meet parallel life syndrome. As the name implies, it’s a common pattern where couples aren’t really living a life together anymore—they’re existing side by side. You know, parallel to each other, with no intersection. Schedules outside of the home barely overlap—one partner’s at the gym, the other lingers in a café. Friend groups are kept separate. Even your downtime, while technically “together” in bed, is spent on your own screens, in different mental worlds.
“Just because you have the time together doesn’t mean that’s quality time,” Ettin points out. “And just because you’re still in a marriage doesn’t mean it’s automatically progressing.” A healthy marriage, even decades in, should feel like it’s moving. It doesn’t have to do so dramatically, but still: You keep each other in the loop, learn from conflict, improve how you communicate, and ultimately deepen the relationship instead of just continuing it.
“You have to tend to [a marriage] just like you would a garden,” Ettin adds—with consistent intention and care. Otherwise, it’s easy to take each other for granted and morph into two individuals who happen to coexist.
So how can you tell the difference between a healthy, slow rhythm and one that veers into parallel life syndrome? Read on for the biggest warning signs experts notice.
1. You make decisions alone—then inform your partner later.
Ideally, your partner should be your default sounding board—not out of obligation, but because they’re someone you instinctively want to include in your world, for stuff big and small.
“So one early sign of parallel life syndrome is rarely thinking to tell your partner about updates or anything important,” Patrice Le Goy, PhD, LMFT, a Los Angeles–based couples therapist, tells SELF. Maybe you got big news—a win at work or a stressful health update—and your instinct is to text someone else. Or you’ve fallen into the habit of making decisions (booking a trip, splurging on nice furniture, signing up for a marathon) without looping them in (or, if you do, only after the fact). Losing that sense of “we,” Dr. Le Goy says, is a subtle indicator of couples running on separate tracks.

