An easy decision to make, as she didn't want to potentially have to kneel on the ground in her rather nice clothing - she had promising plans tonight, after all - so Ari simply told him, "I'll be lookout," and took a few steps away to survey the area, just to make sure no one caught them unawares. Not that Altair couldn't talk his way out of a burglary charge - as had already been proven before - but she preferred not to deal with law enforcement at all, if she could help it.
Fortunately, she doubted it would take him long to unlock the door - Wil was a simple man, in that regard.