United States Vice President Joe Biden officiated Monday the same-sex marriage of two White House employees at his official residence in Washington, D.C.

In a tweet on his official account, Biden posted a picture of himself performing the wedding between Brian Mosteller and Joseph Mahshie.

Mosteller is a special assistant to President Barack Obama and director of Oval Office operations, and has been referred to as “anticipator in chief” by the Washington Post. Mahshie, on the other hand, is a trip coordinator for first lady Michelle Obama.

BuzzFeed News reported that the wedding took place Monday at 4 p.m. This was the vice president’s first time performing a wedding and he obtained a temporary certification from the District of Columbia for the ceremony, according to his office.

The ceremony was attended by family members of the couple.

Biden has been vocal about his support for marriage equality despite objections from right-wing opponents. He is also credited with persuading Obama into taking a political risk by publicly supporting marriage equality before the 2012 presidential election.

The duo won the elections six months after Obama became the first sitting President of the United States to support same-sex marriages in May 2012.