At least they didn't have to argue over who got the middle seat.
Sanders -- unsurprisingly -- was seated on the far left of the plane, as he could be in the window seat of the plane. Warren was also in a window seat, one row behind her opponent.
Warren appeared to be reading something in the photograph, while Sanders was staring out the window.
It's unclear if the two candidates took a moment to chat while the plane was taxiing on the tarmac, but based on some comments from the Vermont Senator this week it would seem less than likely.
Earlier this week, Sanders seemingly swiped at Warren in reaction to a Politico report showing centrists "coming around" to her candidacy.
"The cat is out of the bag," Sanders tweeted. "The corporate wing of the Democratic Party is publicly 'anybody but Bernie.' They know our progressive agenda of Medicare for All, breaking up big banks, taking on drug companies and raising wages is the real threat to the billionaire class.
Sanders denied that tweet was about Warren, but when asked why her campaign has been picking up momentum in recent weeks, he suggested because some voters "would like to see a woman elected."
"I think that there are a certain number of people who would like to see a woman elected, I understand that," Sanders said on CNN. "There are people who would like to see somebody who was younger, and I understand that also. There are a lot of factors out there.”
According to the Hill's Steven Clemmons, who shared the photo of Thursday's flight on Friday, they were heading for Miami -- where they were partaking in a candidate forum ahead of the first Democratic debates next week, which are also being held in Miami.
Warren is the only frontrunner set to appear the first night while Sanders will be sharing the page with former Vice President Joe Biden, Sen. Kamala Harris, D-Calif, and South Bend Mayor Pete Buttigieg.
The two are also slated to appear at a DNC convention in South Carolina this weekend.
Many on social media had some fun at the expense of the two presidential candidates, some expressing sympathy for the man looking at the camera.