McDermott, 25, appeared on the ITV reality dating series in 2018 alongside Collard, whom she also dated after the show.
The pair have been split up since 2019. On Sunday 10 July, it was revealed that Collard, 26, will return to the Mallorcan villa as a bombshell contestant.
Made in Chelsea star Sam Thompson, who has been in a relationship with McDermott since 2019, filmed her reaction to the reveal.
In the video, which was posted to Thompson’s Instagram Stories, the pair are seen sitting on their sofa watching the most recent episode of Love Island.
As the bombshell is revealed, Thompson, 29, comments on the close-up shots of his body and says: “Look at those abs and pecs! Abs and pecs! Wow, he’s jacked! Who’s this guy? Who’s this absolute animal?”
— Love Island Reactions (@LoveIslandTXT) July 10, 2022
As Collard turns to reveal his face, Thompson shouts: “It’s your ex-boyfriend!”
He turns the camera to McDermott, who screams when she realises Collard was on the television screen and says: “No! You’re f***ing joking!”
Love Island fans, many of whom were also shocked by Collard’s return to the show, found Thompson and McDermott’s reactions hilarious.
“The most entertaining scene since Love Island started this year,” one person said.
The most entertaining scene since Love Island started this year 😂😂 https://t.co/YUIBI9UJs7
— Heather McMillan (@Heather13x) July 11, 2022
“This just made my whole life,” another added.
McDermott and Collard dated during their appearance on the show, and for a brief period outside the villa.
However, Collard’s actions on the show in 2018 were divisive, as he moved quickly from contestant to contestant, dumping each one in quick succession.
He coupled up with McDermott after dumping Kendall Rae-Knight and Rosie Williams. After dumping the latter, he was seen smirking while she cried, in a moment that shocked viewers.
After McDermott was unexpectedly evicted from the island on the 25th day of the series, Collard quickly moved on to Casa Amor newcomer Darylle Sargeant.
His behaviour on the show prompted former chief executive of Women’s Aid, Katie Ghose, to release a statement warning that Adam has displayed “clear warning signs”.