Karl hit back, “She would smash you, bro,” to which Alex retorted, “She would smash me and then jump on me.”
Karl cheekily added, “I suppose she is single.”
"And shout at me for being a proud Republican," he added as his co-stars were unable to contain their laughter.
It's the first time we've witnessed the Queen utilising the walking aid since 2003 and 2004 - though that was following a knee operation.
Meanwhile, Karl has responded to whispers that his former co-host, Lisa Wilkinson, is set to drop some major bombshells in her book, It Wasn’t Meant To Be Like This, about her tenuous relationship with the Today host.
Appearing on the Kyle and Jackie O Show, Karl addressed the rumours that he and Lisa don't get along after she claimed that she no longer keeps in touch with her colleague of a decade.
"Lisa and I had 10 years together and in any kind of working relationship there are going to be ups and downs and those things are heightened with breakfast TV," Karl said.
"I think there are probably things that happened over 10 years that aren't going to read well... but I wish her all the best.
"It's not easy, so I wish her all the very best and I think she has every right to go, say and do whatever she wants."