(Photo: Getty Images)

Anyone who's caught Olivia Colman on The Graham Norton Show will know she has a brilliant and slightly wicked sense of humor. And she definitely demonstrated this naughty streak when her old friend Paul Rudd appeared on BBC Radio 1 earlier today (February 17).

Adopting a very convincing Welsh accent to hide her true identity, Colman called into the live radio show hosted by Greg James to chastise Rudd for failing to get in touch during his visit to London. Rudd was taking part in a bit called "Agony Ant-Man," so Colman pretended to be a listener with a personal dilemma. 

"What would you do if you had a really good mate?" Colman asked Rudd live on air. "Like, you know, for over 20 years. You’ve known each other almost half your lives. And then, this friend, he doesn't live in England but he’s come to England and he hasn’t told you about it. And then, not only has he not told you about it, he’s come on to a radio show. What would you do?"

Smelling a rat, Rudd replied: "Oh my god, oh no!"  Colman then asked again if he would be "offended," to which he replied: “Personally, if it’s me, absolutely not. I tend to give everybody the benefit of the doubt. Oh god, what have I done?”

Once she had revealed her true identity, Colman explained that she and Rudd had bonded while appearing together in the 2000 West End production of Eugene O'Neill's Long Day's Journey into Night. "Paul used to come and stay on the floor of our rubbish flat in South London and come for Sunday lunch,” she recalled fondly.

And it was very much a case of "all's well that ends well," because the two actors then agreed to meet up for dinner while Rudd is in England. You can watch the prank in its entirety here. And you can also catch Rudd on The Graham Norton Show on Sunday, February 26 at 11pm EST on BBC America.

Did you enjoy Olivia Colman's playful prank call?