Former U.S. President Barack Obama joked about his ears and gray hair and praised his wife Michelle Obama's "hotness" at the unveiling of the couple's official portraits at the Smithsonian's National Portrait Gallery on Monday.

The Obamas tapped artists Kehinde Wiley and Amy Sherald for the paintings, which will be added to the National Portrait Gallery's collection of presidential portraits.

Wiley and Sherald were the first black artists ever commissioned to paint a president or first lady for the Smithsonian.