Perhaps more than anybody in the Obama administration, Vice President Joe Biden has been the most progressive on the idea of marriage equality. Before Barack Obama gave his support to gay marriage, Biden was on network TV endorsing it in 2012, much to the apparent consternation of the administration.

On Monday, Biden took another step in embracing marriage equality, serving as an officiant to two men exchanging vows.

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 office told Buzzfeed that this was the first time he had officiated a wedding and that he received a temporary certificate to perform the ceremony between Brian Mosteller, the director of Oval Office operations, and Joe Mahshie, a trip coordinator for first lady Michelle Obama.

According to CNN, the ceremony took place at Biden’s home at the Naval Observatory. And the vice president wasn’t the only one who was proud to be a part of the ceremony.