The pals were photographed wearing complimentary ensembles as they arrived for dinner on Thursday night in New York City.
To quote the immortal words of Taylor Swift, "Picture me thick as thieves with your ex-wife."
Turner and Swift, who briefly dated Jonas in 2009, were photographed arriving separately at luxury Hotel Barriere Fouquet for dinner -- but appeared intentionally coordinated in their ensembles.
The Game of Thrones alum wore a white Bleusalt T-shirt and grey maxi-skirt, adding a pop of color with red ballet flats and a multi-colored Louis Vuitton bag.
For her part, the "Cruel Summer" singer opted for a black top and wide-leg gray pants with red heels, carrying a black bag that appeared similar in size to Turner's. Both women wore their long hair down and straight, while accessorizing with complimentary gold chain necklaces, bracelets, and gold rings.
After their dinner, a source tells ET that Turner and Swift partied downstairs at the new cocktail bar under GANT, called The Mulberry, from 11 p.m. until 2 a.m. It opened earlier this year and caters to the fashion elite and A-listers.
The night out came hours after Turner sued Jonas in an effort to get their children -- 3-year-old Willa and a 1-year-old daughter whose name they've not made public -- to the U.K. The court docs revealed that the pair met recently to discuss their separation, but it seems the custody arrangement has become a point of contention.
Jonas filed for divorce from Turner on Sept. 5 after four years of marriage.
On Tuesday, Turner and Swift were spotted arm-in-arm outside West Village haunt Via Carota after enjoying a dinner with friends. From there, they headed to Temple Bar, a nearby nightclub, where they stayed for a couple of hours before leaving around 11 p.m., according to a source.
"Sophie seemed to be happy and enjoying the night," an eyewitness told ET. ET's source added, "They seemed to be having the best time -- they were laughing and chitchatting with the waitstaff and drinking martinis."
Meanwhile, a second source told ET that the two women "have always liked and respected each other."
"They are fans of each other and have been friends for a while," the source said. "Sophie doesn't care that Taylor dated Joe. It was so long ago and in the past. Taylor has a good time when she's with Sophie and they enjoyed some fun girl time together last night."