Vice President Joe Biden Officiated His First Wedding for Same-Sex Couple

— -- Vice President Joe Biden officiated his first wedding ever -- and it was for a same sex couple.

Biden officiated over the wedding of two longtime White House staffers, Brian Mosteller and Joe Mahshie, at the Naval Observatory on Monday, his office said.

Posting a photo of the ceremony on Twitter, Biden wrote, "Proud to marry Brian and Joe at my house. Couldn't be happier, two longtime White House staffers, two great guys."

His office said the vice president obtained a temporary certification from the District of Columbia to preside over the wedding ceremony, which was attended only by the grooms' families.

Biden's wife, Jill, later tweeted: "Love is love!"

The Vice President publicly endorsed same sex marriage in 2012.

ABC News' Arlette Saenz contributed to this report.