Vice President Joe Biden married two gay White House staffers at his residence in Washington, D.C. on Monday.

The ceremony marked the first time Biden has married a couple and also the first time he has married a same-sex couple.

Biden's office told BuzzFeed that Brian Mosteller and Joe Mahshie's wedding took place at 4 PM Monday at the Naval Observatory, the residence traditionally occupied by the Vice President.

Biden shared the news on Twitter with a photo from the ceremony. He wrote, “Proud to marry Brian and Joe at my house. Couldn't be happier, two longtime White House staffers, two great guys.”

Proud to marry Brian and Joe at my house. Couldn't be happier, two longtime White House staffers, two great guys. pic.twitter.com/0om1PT7bKh

— VP Biden (Archived) (@VP44) August 1, 2016

Biden's wife, Dr. Jill Biden, retweeted the Vice President's tweet, adding, “Love is love!”

Love is love! —Jill https://t.co/xDrz2m9qf2

— Dr. Biden -Archived (@DrBiden44) August 2, 2016

Mosteller is the director of Oval Office operations while Mahshie is a trip coordinator for Michelle Obama.

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Biden obtained a temporary certification from the District of Columbia in order to perform the ceremony.

Biden endorsed marriage equality in 2012 in a now-infamous interview on Meet the Press, putting him ahead of President Obama on the issue and sending The White House into a media tailspin at the time.