The former Big Brother contestant was reunited on screen with the ex-Little Brother host, 18 years after she was first interviewed by Dermot on the spin-off show.
Alison was a housemate on the 2002 series of the reality show before she went on to forge a career as a TV presenter, and as she and Dermot got started with This Morning, they took a moment to remember their first meeting.
Alison, who usually presents This Morning’s showbiz segments, said: “The last time I saw you really was in 2002. You were the first person to interview me.”
Dermot then played a clip of Alison’s audition tape for Big Brother, while she also showed his opening link from his first-ever Little Brother.
“I look so young!” Alison observed.
“Oh wow! I miss that hair,” Dermot said after seeing a shaven-headed version of himself from 2001.
He added: “There was like a Big Brother aficionado who put something online a couple of weeks ago, my first ever show.
“I tweeted after saying that someone was on the espresso, I was so excited to be on live telly. I’m excited today!”
The pair then shared a celebratory dance in the studio before getting on with the rest of the show.
Viewers were absolutely loving seeing Alison and Dermot on screen together, with many praising the duo on Twitter.
During the summer, various guest presenters have taken the helm of This Morning each Friday, as regular Friday hosts Ruth Langsford and Eamonn Holmes have stood in for Holly Willoughby and Phillip Schofield from Monday to Thursday.
After hosting her second live show, Alison thanked fans and her bosses on her Instagram.
She wrote: “Two weeks of presenting the main Friday show with @rochellehumes and @radioleary has been a absolute pleasure.
“Thanks @thismorning and @itv for the opportunity and everyone in the gallery and behind the cameras for making me feel so comfortable. What a show @thismorning is.
“I never take it for granted how amazing lucky I am to have such a wonderful job #blessed #lucky #love,” she added.
Dermot also wrote: “Loved rolling with my old compadre @alisonhammond55 today on @thismorning.”
Holly and Phil are set to resume presenting duties from Tuesday 1 September.
Prior to their break, Holly spoke of her hopes to be reunited with her glam squad upon her return, after months of doing her own hair, make-up and styling during lockdown.
This Morning airs weekdays at 10am on ITV.