06/29/2011 AT 11:15 AM EDT
think he's "so cute" and "so handsome" – but she's not talking about boyfriend Justin Bieber
In a YouTube video
Gomez posted Tuesday night, the starlet gets starstruck when she meets her longtime celeb crush
, Shia LaBeouf
Thanks to some coy plotting by her pals, who told her she was about to meet a fan, Gomez, 18, bumps into the actor, 25. "I'm so sorry to bother you," she tells him.
"Thanks for being so sweet to me," he replies. "You're really sweet to me."
Before parting ways, the two hugged and posed for pictures. "I admire you," Gomez continued to gush.
But so much for playing it cool. Once she's back with her girlfriends, Gomez spins into fan-girl mode.
"He's so cute," she says. "Oh my gosh, he's so handsome."