Bradley Cooper and Suki Waterhouse at the White House on Feb. 11
02/18/2014 at 01:00 PM EST
Just call him Commando in Chief.
star Bradley Cooper
revealed that when meeting President Barack Obama
and French officials last week, his outfit was missing one piece de résistance: underwear.
Cooper, 39, has gained about 15 lbs. in four weeks for an upcoming role, he said Monday on The Ellen DeGeneres Show
. He decided to dust off his Golden Globes
tux for Tuesday's White House State Dinner
, not realizing the suave suit no longer fit.
"I'm getting dressed like 10 minutes before I was supposed to go, and literally the pants go up to like here," Cooper recalled
, pointing to his thighs. "I just started laughing, actually. This is hilarious. I'm going to meet the president. So I had to go commando, number one, because there was no room at all."
Girlfriend Suki Waterhouse
didn't seem to mind. The 22-year-old model stuck by her man's side throughout the night as he chatted with dignitaries and fellow actors like Veep
's Julia Louise-Dreyfus
Just how close was Cooper to a wardrobe malfunction
"They were crazy-town tight," he told DeGeneres
of his pants.