Simu Liu reveals why he wore shorts, slippers in THAT 'Avengers' photo

Simu Liu is still embarrassed about his photo with the Avengers: Doomsday cast.

Liu appeared on the Tonight Show Starring Jimmy Fallon and recalled meeting Marvel’s biggest star, Robert Downey Jr. while filming Avengers: Doomsday.

Speaking to Fallon’s audience, Liu said he wanted to talk about the photo and explain why he seems so "underdressed."

Since he had to get into his costume to play Shang-Chi that day, Liu went to set in "short-shorts and flip-flops."

However, Downey called him over to say hi, so the actor had to comply.

"This was my first-time meeting Downey by the way," he said, adding that he was "embarrassed" about his dressing.

"I was the only one of these people that had to work that day," he continued. "So I showed up to work ready to shoot. I wasn’t trying to look pretty."

"I get a text in the middle of the day saying Downey wants to see me after work," he recalled, adding that he exclaimed, "No!, I’m wearing short-shorts and flip-flops."

"And they were like, No, Downey wants everyone to come in and say hi,'" the Kim’s Convenience star recalled.

"So I show up and literally the first thing he said was like, 'Oh, look at you. Oh, that’s a choice!!'"

Liu added, "I was like 'God!'"

The photo featured Chris Hemsworth (Thor), Channing Tatum (Gambit), Paul Rudd (Ant-Man), Robert Downey Jr. (Doctor Doom), Ebon Moss-Bachrach (The Thing), Vanessa Kirby (Invisible Woman), Winston Duke (M’Baku), and Anthony Mackie (Captain America) along with Simu Liu.

The actors had assembled to promote the latest Marvel film, Thunderbolts. Downey shared the photo on his Instagram handle, writing, "Just wow!!! Dinner and a show with the Old Avengers. So cool, fresh, and deep. Big congrats to the New Avengers (and Bob). #thunderbolts."