When your rent takes up half your paycheck, splitting a one-bedroom with a romantic partner starts looking pretty appealing. And apparently, a lot of Americans are thinking the same way.

Nearly a quarter of singles say they'd consider moving in with a partner faster than they normally would just to save money, according to new research from DatingNews.com and the Kinsey Institute at Indiana University. It's the kind of decision that makes perfect sense on a spreadsheet but might give relationship therapists heartburn.

Justin Lehmiller, a senior research fellow at the Kinsey Institute, notes that relationship timelines used to be much shorter historically. People met, moved in, got married—all in pretty quick succession. But as Americans started delaying major milestones like marriage, those timelines stretched out considerably.

"But I think we're at the beginning of seeing things change a little bit in terms of how people are thinking about and approaching relationships," Lehmiller told CNBC.

Gen Z Isn't Waiting Around

Among all the generations studied, Gen Z shows the most willingness to hit the fast-forward button on relationship milestones for financial reasons.

A striking 38% of Gen Z respondents said they'd cohabitate earlier to save money, and 26% would even get married sooner. Compare that to millennials at 29%, Gen Xers at 21.8%, and boomers at just 11% willing to speed up their move-in dates.

The marriage numbers show an even steeper generational divide. Only 20% of millennials, 15% of Gen Xers, and 7.2% of boomers said they'd compromise on their wedding timelines for economic reasons.

Lehmiller attributes these differences largely to financial security—or the lack thereof. "Gen Z is really the most financially strapped generation right now," he explained to CNBC. "They seem to be more likely to view cohabitation and marriage as a way of alleviating some of the financial strain that they're experiencing."

The Other Side of the Coin

Here's where things get interesting. While some singles are ready to speed things up, others are pumping the brakes entirely because of economic anxiety.

Overall, 33% of respondents said economic challenges actually made them more hesitant to commit to relationships. About half of Gen Zers cited money as a factor making them cautious around relationship milestones, compared to 37.3% of millennials, 30.2% of Gen Xers, and 20.1% of boomers.

So the same generation most willing to rush into cohabitation is also the most likely to hesitate? Lehmiller says this "might sound paradoxical at first, but it's not. It simply reflects the fact that economic issues don't affect everyone the same way."

Why Experts Say Slow Down

Before you start browsing apartments with your three-month-old relationship, Lehmiller has a word of caution.

"Accelerating your relationship timetable is risky," he told CNBC. "You might end up in a situation where you find that this person is not actually a good match for you long term."

The math here is pretty straightforward. Breaking up with someone you live with gets expensive fast. You're looking at moving costs, security deposits, possibly breaking a lease, and setting up a new place from scratch. All those expenses can quickly exceed whatever you saved by splitting rent for a few months, leaving you financially worse off than when you started.

In other words, a bad roommate is annoying. A bad roommate you're also breaking up with? That's a financial disaster.