ET has learned that Oprah Winfrey shared a private dinner last night with President-elect Barack Obama and Oprah's best pal Gayle King tells us all about it.

Gayle tells ET the dinner, which she also attended with about 100 people at the historic Blair House across the street from the White House, was "top, top secret" and wonders how word got out. "You guys are good! How did you hear that? Boy you people are good."

"It was a buffet dinner, so everything you'd expect in a buffet was there - as someone who's trying to fit into a red hot inauguration dress, a buffet is not my friend," Gayle said.

Gayle said she wasn't sure what Oprah would be wearing to the inauguration on Tuesday, but added, "she will look stunningly gorgeous whatever color or designer she chooses." Gayle herself said she will be wearing something red from designer Angel Sanchez.

Gayle hosts a radio show on Sirius XM's Oprah and Friends channel.