Nate Berkus, Jeremiah Brent on December 3, 2012 in NYC. Credit: JONATHON ZIEGLER/ via AP Images

Nate Berkus is off the market!

The interior designer, 41, is dating Rachel Zoe's former assistant, Jeremiah Brent, a source confirms to Us Weekly.

According to the New York Post's Page Six, Berkus was seen getting cozy with The Rachel Zoe Project star at Barneys in NYC on Sunday, Dec. 5.

"They were kissing at the sunglass rack in the men's section," an eyewitness told Page Six. A photo of the twosome ice skating with a pal was also posted on Twitter that same day, and Brent attended Berkus' book signing for The Things That Matter at Bergdorfs.

The stylish guys were also photographed together on Monday, Dec. 3 at a holiday party in NYC benefiting Faith in America and The Tyler Clementi Foundation.

"So proud [of] Nate Berkus. Beautiful evening promoting truth, love and education Love is love," Brent tweeted Tuesday.

Berkus was previously in a long-term relationship with Brian Atwood from 2007 to 2009. When Atwood became engaged to Dr. Jake Deutsch in August 2011, Berkus told Us, "We are still in touch and I am really, really happy for him."