In the short sketch, Damon and Buster were pretending to be staff at a hotel in Ireland where the ITV chat show host was staying.
Playing an alternative version of herself, Lorraine became more annoyed as the character was shown to her room by the two men who made a series of hiccups along the way.
However, after finally settling into her room, Lorraine made a phone call to the reception where it appeared she was speaking to Dermot.
Though, it wasn’t until after Lorraine put the phone down did she break from her character to reveal an apparently unplanned moment which had arisen.
In the sketch, Lorraine wanted to make a complaint about her room, therefore ringing the reception for Dermot to answer: “Hello, reception, how can I help?”
Staying in role as an annoyed customer, Lorraine told the Irishman: “Yes, listen, there’s already someone in this room. It’s occupied.”
With Dermot also playing a role of a thoughtless receptionist, he asked: “Are you sure?” to which Lorraine replied: “Positive.”
However, when Lorraine put the phone down, she broke from character into a fit of laughter and explained her reason for doing so.
The camera crew also burst into hysterics as the presenter explained: “Somebody at the phone went, ‘Reception, can I help you?’” pointing out she hadn’t been speaking with Dermot.
Though, Lorraine dropped back into character as the hotel guest made more complaints, ringing down to the reception to ask about another query which had arisen.
Answering the phone, Dermot said: “Hello Miss Pseudonym,” to which a frustrated Lorraine said: “I ordered a room with a view.”
Continuing in the comedic style, Dermot asked: “Well, which window you looking out?” To which Lorraine reluctantly replied: “The north window?”
As the comedy of errors continued, Lorraine’s character packed her bags and headed down to the reception to cancel her stay.
The news Lorraine would be appearing on the show in some format was revealed last month when Mrs Brown actor Brendan O’Carroll spoke on the ITV chat show.
During his interview with Lorraine, the Irish comedian revealed he almost didn’t play the character of Agnes Brown and came upon the role by mistake.
Brendan revealed to Lorraine although he scripted the character, he came to play the housewife when the actress who was meant to play her rang up sick.
Brendan explained: “I thought I would do her lines and then when she was better we would dub her lines in.
“So just for authenticity, I did that voice, that Mrs Brown’s voice, and when it went to the edit it was the editor who said, ‘Who’s that actress playing Mrs Brown?’ and I said, ‘Don’t be ridiculous. That’s me.