Actor Ansel Elgort was left red-faced at an Oscars afterparty last month (Feb15) after his mother failed to recognise action star Bruce Willis and quizzed him about his success.

The Fault In Our Stars actor took his opera director mum Grethe Barrett Holby as his date to the Academy Awards and although she enjoyed Hollywood's big night, she was clueless about the celebrities her son introduced her to.

Elgort reveals, "She loved it... but she had no clue who anyone was, which was hilarious.

"We met Steve Carell, and I was like, 'Hi Steve, I'm a big fan...' and he said, 'Oh yeah, I know who you are Ansel, it's good to meet you...', which was cool, and then we talked for a little bit and when he left I said, 'Mum, you know who that is, right?' She said, 'No.' (I said), 'Mum, that's Steve Carell...! He was in The Office, 40-Year-Old Virgin...' (She said), 'I've never heard of him.'"

But Elgort insists that wasn't the worst of it as his mother went on to embarrass him in front of Die Hard star Willis and his model wife Emma Heming, who had previously worked with the 20 year old's father Arthur Elgort, a Vogue fashion photographer.

He continues, "My mum is ridiculous. We were at a party... Bruce Willis is there with his wife... They were introduced and my mum said, 'Hi, what's your name?' He said, 'I'm Bruce.' My mum said, 'Oh, well, what do you do...?' He said, 'I'm an actor.' She said, 'Oh, my son's an actor. How's it going for you?' He said, 'Yeah, it's going pretty good.' I was, like, dying!"