Ahead of the show, Holly posted her daily #HWstyle picture to Instagram.
She revealed that she was wearing a £260 Sandro Paris black dress with a faux pearl beading on the lapels.
View this post on Instagram
However, while her followers lapped up the chic style, Phil lowered the tone as the show went live.
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"Your necklace has broken by the way," he quipped with a cheeky smile.
"Got my pearls on today," a grinning Holly replied, stroking the pearl embellishment.
"So it’s been on 11 minutes and we’ve had Holly Willoughby talking about a pearl necklace and a woman rubbing a squirrels head that looks like something else," one outraged viewer said.
@thismorning bit early for @hollywills talking about her pearl necklace.
"A broken pearl necklace, as pointed out by @Schofe. This is pure daytime smut," said another.
Others found the host's cheeky quip funny, though.
"Loving Holly's pearl necklace," said one with a wink.
"@thismorning bit early for @hollywills talking about her pearl necklace," said another, adding a series of crying with laughter emojis.
Jokes aside, over on Instagram, Holly's followers were loving her look.
One said: "I adore the dress. You look stunning as per usual."
Another added: "Pearls all day every day!"
"Absolutely stunning," another fan said.
"OMG love that frock!" exclaimed another.
"Love the dress, beautiful," said another.
"Great dress, mind you, you could wear a bag for life and rock it," another quipped.
"You guys are hilarious"
Others commented on the chemistry between Holly and Phil.
"I love watching you and @schofe you guys are hilarious!!! Thanks for such great entertainment," said one fan.
As the show progressed, the saucy pair indulged in even more risqué banter during a cooking segment with John Torode.
It happened as John told the pair how to recreate a McDonald's Egg McMuffin.
"So I'm buttering my muffin," a cheeky Holly giggled.
"Is it nice buttering your muffin there, Holly?" John asked.
"Funniest show I've seen"
One viewer branded John a "perv" for the comment and said there was "no need on morning TV".
However, others found it funny.
"Watching you today and seeing Holly's pearl necklace, a squirrel getting its head rubbed off and John nearly setting his kitchen on fire is literally the funniest show I have ever seen!" one happy This Morning viewer tweeted.
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