It’s not every day that you move to Washington and somebody throws you a big party. But Julian Castro, the new secretary of Housing and Urban Development, was the star attraction Monday night at an event honoring top Latinos in the Obama administration.

Just hours after being sworn in, the 39-year -old Castro capped his first full day on the job by attending a reception hosted by the Congressional Hispanic Caucus Institute called “Celebrating Latino Cabinet Members.”

But not everyone being feted actually has a seat at the big table.

In addition to Castro, there was Labor Secretary Thomas E. Perez and Maria Contreras-Sweet, the administrator of the Small Business Administration. All three have seats in the Cabinet room as the SBA job was elevated to the Cabinet by Obama. But the reception also honored Katherine Archuleta, director of the Office of Personnel Management. That’ll be seen as a stretch by some since the OPM director’s job is not officially considered Cabinet level, according to the White House Web site.

But three’s just a crowd and four is a good reason to party, so the CHCI event in the Russell Senate Office Building was packed with aides, interns, lobbyists and lawmakers, including Reps. Joe Garcia (D-Fla.), Judy Chu (D-Calif.), Tony Cardenas (D-Calif.), Grace Napolitano (D-Calif.) and Linda Sanchez (D-Calif.).

As the new kid on the block — and the one with the biggest national political aspirations — Castro was clearly the star of the show. He was mobbed when he walked in by interns, lobbyists and operatives, who quickly whispered words into his ear and begged for a selfie. He obliged, smiling and posing for pictures before moving on.

Sen. Robert Menendez (D-N.J.) introduced Castro to the room. “I don’t have too many people with the last name Castro that I like,” joked the Cuban-American critic of the Castro regime in Havana.

When it was his turn to speak, Castro acknowledged “my baby brother,” Rep. Joaquin Castro (D-Tex.), who was standing near the front of the stage. The congressman was born one minute after the secretary.

For those who keep score of such things, the event was sponsored by several corporations with business before the four administration officials, according to a program for the reception. Sponsors included Bank of America, Cargill, McDonald’s, Samsung, Mary Kay, the National Association of Realtors, the National Association of Minority Automobile Dealers and Toyota. The auto company operates a large production facility in the San Antonio area, where Castro was mayor until last week.