As Barack, 63, Bill, 78, and Hillary, 77, entered the U.S. Capitol rotunda in Washington, D.C., on Monday for the 78-year-old’s historic swearing-in ceremony, people at the Capitol One Arena could be heard loudly booing.

Michelle Obama was the only spouse absent at the funeral service at Washington National Cathedral, where her husband and Trump were seated next to each other and chatted and laughed like old friends despite the history of political animosity between the Democratic former president and the returning Republican.

WEST PALM BEACH, Fla. -- Former first lady Michelle Obama will skip the inauguration of President-elect Donald Trump, the second time in two weeks that she is not attending a gathering of former U.S. leaders and their spouses, but former Presidents Barack Obama, George W. Bush and Bill Clinton will be there.

The planned absence Monday follows another notable absence last week at the state funeral of former president Jimmy Carter.

The inauguration is the second gathering of U.S. presidents and their spouses that Michelle Obama has missed in recent weeks.

According to NBC News, the Obamas, Clintons and Bushes won't be at the traditional lunch that follows Trump's swearing-in.