Isla Fisher snuck Sacha Baron Cohen's Ali G costume into the Oscars inside her Spanx

Sacha Baron Cohen's wife, actress Isla Fisher, revealed how crucial she was to Cohen's surprise Oscars appearance as character Ali G.

Cohen had been on probation after he appeared in character from his movie "The Dictator" and spilled late North Korean dictator Kim Jong-il's "ashes" on Ryan Seacrest during a red carpet interview.

"He managed to wrangle his way in," Fisher explained on Thursday's "Jimmy Kimmel Live!" "But he said, 'I want to sneak in and do Ali G, but I can't fit it on my body because they're going to put me through metal detectors, and be ultra-suspicious, and, sweetie, will you fit giant yellow glasses, a hat, a glove, and a beard inside your Spanx?'"

Yes, Spanx has never had a better spokesperson for the undergarment's ability to keep it all in and looking svelte.

"You're used to taking hair off down there to go to events, instead of adding considerable amount of beard. And then I had to fit the yellow glasses to insert them too. So it was a challenge to sit down," she went on.

In a video, Fisher showed how she and Cohen snuck away to a bathroom during the Oscars in order to piece together his costume. Fisher applied his beard and admitted, "I am really stressed out, actually..."

"We had to sneak in there for like 45 minutes," the "Now You See Me" actress said. "People were banging on the door, and 'Sacha's got to come out now,' and they're wearing headsets, and I'm really scared of authority. I hate being told off. I'm a real goody-two-shoes."

To buy some time, she told the Oscars crew that Cohen was having stomach problems. But then they brought her Tums. "I had to eat them."

That's love.

Watch Fisher describe the entire crazy scheme below: