When a girl walks down the street in such a short skirt and with an anal plug, it's clear that she's looking for an adventure for her ass. Licking ice cream is just an added touch to this image of a bitch. So her verbal signs were quickly understood and she even squirted while being fucked in the ass.
The guard wasn't confused and quickly came up with a punishment for the thief, fitting his straining aggregate into her mouth and pussy.