Alison Brie is still red-faced about her first encounter with Ellen DeGeneres because she flashed the TV host a prank photo of a stranger's genitals.

The GLOW star was showing off a rude snap she had been texted on her phone during a session at the gym and didn't realise Ellen was right there.

Recalling the pair's embarrassing first meeting during an interview on The Ellen DeGeneres Show on Monday, Alison said, "I was rushing into the gym and I had been receiving some sort of prank texts that morning. And, you know, I've known our trainer Jason for a while, so I share things with him all the time.

"I came in bursting like, 'Everybody, you gotta see what I've been receiving on my phone!' And as I go to show him, there you are, just passing by, you're sort of just lunging by. And you were like, 'What's going on?' And I whipped around - I think before I realised it was you - and I was like, 'Look at this!' And, you know, it was a photo of a man's nether regions."

"(It was) nobody I knew, a stranger!" she added. "I had been getting those texts all morning and I really, really kind of put it in your face and I apologise."