The 51-year-old appeared to lash out at a Good Morning Britain viewer, who questioned their relationship over Twitter.
A person tweeted Piers, saying: “#gmb have @susannareid100 and @piersmorgan had a fallout? They seem a bit distant today.”
The former Britain’s Got Talent judge hit back with: “We're both sick. And no, not of each other.”
His tweet comes as Susanna, 46, bestowed a cheeky gift on him: a set of de-motivational pencils which featured slogans such as: “Think positive, not everybody hates you.”
Piers could be seen in stitches as he read out the slogans on the pencils to the rest of the Good Morning Britain cast and crew.
He described it as the “best present I’ve ever been given” as he laughed and told viewers that Susanna was “obsessed” with motivational pictures and affirmations.
One of the slogans read: “Teamwork means: sharing the blame," leading Susanna to quip: “Tell me, I know all about that! Sharing the blame!”
Piers Morgan hits out at a Good Morning Britain viewer
Piers Morgan launches in a rant after getting a gift from Susanna Reid
We're both sick. And no, not of each other
After reading them out, Piers went on a rant about positive thinkers as he addressed the camera: “These are brilliant because the point is we are in such a snowflake generation.”
His words led Susanna to cringe as Piers continued: “Where everyone has to be a victim. Everybody has to have a problem. Everyone has to whine and wail. Then on the positive be motivated to be better and wonderful and lovely.”
He added before Susanna could chip in: “And the reality of it is it ain’t as bad as you think it is. It’s a lot better than it used to be. We are all going to be just fine!”
Piers Morgan has a rant on Good Morning Britain
GMB: Piers Morgan & Susanna Reid take on politicians
Tue, January 24, 2017
Good Morning Britain hosts Piers Morgan and Susanna Reid talk politics with Theresa May, Nigel Farage, Donald Trump and more.
1 of 14
Good Morning Britain talks politics with Theresa May, Donald Trump, Nigel Farage, & more
Owen Jones and Piers Morgan clashed on Good Morning Britain
Today’s edition of the ITV show proved to be an eventful one as Piers clashed with journalist Owen Jones over Donald Trump.
Owen, 32, was heard holding his own during the fiery debate between the two men as the writer told Piers: “This is a monologue, this isn’t an interview!”
As Owen tried to speak, Piers continued, leading the former to exclaim: “The production staff are laughing at you!”
Good Morning Britain airs weekdays on ITV at 6am.