Piers Morgan stunned his Good Morning Britain co-host Susanna Reid this morning when he pointed out guest Lord Alan Sugar's weight gain.
The Apprentice star was on the couch to talk about the new series of his show, which continues tonight on BBC One.
But his frenemy Piers - they just love to hate each other - seemed more preoccupied with mocking his frame.
The anchor said: "Are you chunking up a bit?"
Susanna Reid, patiently sitting there as the boys sparred with each other, was appalled by the probing question/dig.
"Is it appropriate to ask if someone has put on weight?," she said.
And that's a very good question! Is it? Most people notice when they've gained a few pounds anyway, so how is someone else pointing it out going to help?
Is it appropriate to ask if someone has put on weight?
Is the subtext: you need to drop some timber? You looked better before? I don't find you as attractive?
In this case, Lord Sugar is so thick-skinned, he didn't seem to care and replied: "I have put on 18lbs.
"Never you mind about me son," he continued. "Pot kettle, I saw you prancing around in the summer. You looked like a beached whale."
He then suggested that Piers' wife, Celia, wants him to lose weight.
The pair - who verbally joust on Twitter most days - ended up agreeing to a weight-loss challenge, after hopping on some scales in the studio.
Lord Sugar was revealed to weigh over 14 stone, which amused Piers, who himself weighed in at 16 st 6lbs - who justified that as being right for his huge frame.
As Sugar called Piers "blubber boy", his nemesis hit back with "chubster".
The two over-grown schoolkids will now compete to shift the most weight between now and December - whoever loses the least will donate £5000 to Great Ormond Street Hospital.
So at least the insult will eventually benefit a good cause!