The time has finally come for you and your significant other to take that trip you’ve been planning for ages. Your bags are packed, your snacks are accounted for, and you’re basically dreaming about the fresh environment where you’ll surely clock in some A+ quality time and off-the-walls vacation sex. But then all of a sudden, you’re rustled from your trance because “this route has too many tolls and now we’re going to have to drive through the city, and are you even listening to the GPS? It says turn right. RIGHT, you idiot.” To be clear, it’s not just you; fighting on vacation, even in the scope of happy, healthy partnerships, is totally a thing.

In fact, bickering with your partner on the road is basically just par for the travel course. And if your final destination is to somewhere decidedly not-sexy, like the twin bed in your parents’ home, expect tensions to be extra high. But still, no matter whether the trip was born from an obligation or was supposed to be leisurely in nature, what fuels this couple arguing fire in the first place? Why are we so inclined to start picking fights for no reason with our partner when we’re traveling?

“When people are overtired and exhausted, they have no patience for dealing with even one more drop of stress from their partner.” —relationship therapist Laurel Steinberg, PhD

According to relationship therapist Laurel Steinberg, PhD, more than a few factors fan these flames, but there is one overarching core reason to understand: traveling itself is inherently stressful. “You have to take taxis, planes, cars, and boats just to get to your destination, which is exhausting and annoying, and then, when you get to the destination, you often have to adjust to the time change and then get up early to go on tours to get the most out of your expensive vacation,” she says. “When people are overtired and exhausted, they have no patience for dealing with even one more drop of stress from their partner. As a result, their low-frustration tolerance manifests as a quick temper, and boom: a fight breaks out.”

Sure, it may sound like a champagne problem, but the exhaustion component is no joke. Research shows that couples tend to fight more when they get a bad night of sleep, and even the most wonderful neck pillow can only do so much for in-transit snoozing.

Lack of sleep quality and quantity isn’t the only issue contributing to increased stress levels while away. Also at play is the phenomenon of being unable to unplug—both in general and regarding work-related responsibilities. Because even though you’ve saved up your vacation days for whatever excursion you’re on, many still find ignoring their work emails to be difficult in practice—and it takes a toll. In fact, one survey by organizational consulting firm Korn Ferry showed that the habit of working while traveling is what couples fight about the most while away.

With the previously mentioned components remaining constant, consider, then, what might happen if something on the itinerary doesn’t go according to plan. Because, let’s be real: that’s very likely. When things go wrong, the tension is ratcheted up even higher. So while traveling may bring couples closer, perhaps there’s such a thing as too close, leading to volatility and a constant butting of heads.

Fighting on vacation might just be a part of every travel itinerary no matter how happy you and your partner are. But to keep things as calm as possible, exercise self care and lean into mindfulness—and always, always pack some extra snacks.

Even if you don’t spend a lot of time fighting on vacation, you might still feel exhausted when you return home. Here’s why you feel like you need a vacation from your vacation, and here’s how a happiness expert says you can maximize the good feels while you’re still away.