Rumours have been swirling that the "Kiss You" stars are planning something special to mark the boyband's 10th anniversary, and the "Strip That Down" hitmaker added fuel to the fire with the clip, as fans predicted something is going to happen on 23 July (20).
Sharing an apparent screen recording from his phone, Liam began calling his pal, who was saved under the name "H", with "Adore You" singer Harry picking up the call.
"Hey man," says Liam, as Harry replies, "Hey, how's it going, good?"
"Yeah good. Someone's got the giggles," Liam quips as the clip of Harry showing off his cheesy grin continues on a loop as Liam pauses to say, "It's getting weird now - I'll speak to you later?"
There's no response from Harry before Liam pulls a face and ends the call on his pal.
While the cryptic video left some fans puzzled, others have taken it as a sign that the boys will reunite to celebrate their 10th anniversary at the end of the month.
"OMG (Oh My God) DONT EVEN PLAY WITH ME LIKE THIS IM SCREAMING," one user commented, while another added, "IS THIS ACTUALLY REAL OR AM I JUST DREAMING."
A third mused, "SOMETHING IS GOING TO HAPPEN ON THE 23RD JULY" - referencing the exact anniversary of the date the group was put together on "The X Factor U.K."