The Good Morning Britain host was ranting about a Netflix documentary that claims plant-based diets can help improve men’s sexual performance when the unlikely proposal came.
Piers, 54, was unconvinced by the vegan theory, branding it "utter nonsense".
But his mouth nearly got him into a very awkward situation after he claimed he "didn’t need" to boost his stamina when Gemma offered to put him to the test.
"You could go vegan for a while, couldn't you?" his fellow host Susanna Reid baited him.
And after Piers insisted his form in the bedroom would not be boosted by switching to meals packed with tofu, guest Gemma piped up and suggested he might go vegan for a while so his performance could be compared with and without meat in his diet.
That escalated quickly!
"Who's gonna try me out?" Piers enquired.
"Me!" declared Gemma, leaving Piers in hysterics.
"That escalated quickly!" added a startled Susanna.
However, a few hours later on Instagram, Piers snubbed the idea of giving his virility a run-out with The GC.
"This is unlikely to make me turn vegan," he commented on a screengrab of an online story about what had happened between them.
"Any guy would be lucky to have her," protested one commenter on the snap.
Another person added: "The mind boggles!"
- Good Morning Britain airs on weekdays from 6am
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