We’ve got a long holiday weekend coming up. Though a lot of American workers will take time off, many won’t fully unplug and will be checking emails and stressing about what tasks await them when they get back, according to a new survey on office culture by the Harris Poll.

The poll also found that even though workers aren’t taking full advantage of time off, they’re still finding time to chill — just on the down low.

Americans are kind of bad at taking vacation, especially younger workers. More than 80% of Millennials and Gen Z say they’re not taking their allotted PTO, per Libby Rodney with the Harris Poll.

“You’d think they would be taking all their time off based on the work-life balance that they desire, but there’s definitely a tension when it comes to the reality of being at work,” she said.

Though some young workers are still carving out down time, “they’re just quiet vacationing instead,” said Rodney. 

Like taking time off without telling their bosses. They’re also “moving their screen to their mouse to seem active or online,” she added. 

This shows many workers are feeling pressure to be constantly on, according to Ann Skeet, a professor of leadership ethics at Santa Clara University.

So, they’re making a rationalization: “If I’m going to be overworked and working beyond regular hours and on weekends, and then I can take my paid time off, then at a minimum, I’m going to have some flexibility in my day where I’m deciding when I’m working and the nature of the work,” she said.

Taking PTO shouldn’t just be policy, she noted, but part of company culture.