"You can NEVER be better than Miley," another raged.
Others focussed on Gabriella's ex-boyfriend, Matt Healy, from the pop band The 1975.
"Lmao you really left Matty for Liam?!?" they commented.
Since the Aussie model was photographed meeting Liam's family earlier this week, insiders have opened up about their whirlwind romance, with one source close to The Hunger Games actor telling Radar Online they've been secretly dating for some time now.
“They’ve known about each other for a while, but he just started seeing her for a few weeks now,” the source told the outlet, adding he's formed a "strong connection" with the 21-year-old. “Liam is very close with his family, so he wouldn’t introduce them to a girl unless it was serious.”