The sibling trio - Sophia, 20, Sistine, 18, and Scarlet, 14 - has confessed to nabbing the "Hunger Games" star's digits from their father but said nothing ever worked out from it, reported Harper's Bazaar.
"When I was little I use to go through my dad's phone and take numbers," Sophia said.
Whilst Sistine added, "I called him. He never answered."
And Liam isn't the only celebrity the girls have got starstruck around. Sophie said she was "really bumbly" with Ryan Reynolds, while Sistine's "heart skipped a beat" when Leonardo DiCaprio remembered meeting her. Scarlet said she "fainted a little" on coming face to face with Ryan Gosling.