Check out the pics ... Justin posted the pic above on Instagram Sunday with the caption, "Lord knows." Lots of people thought the chick in the pic was Kourtney.
Turns out ... not at all. The pic below, which was taken around Newport Beach, shows the woman in question ... and it's not Kourtney. In case you have any doubt, check out her shoes.
BTW, as we reported, Justin and Kourtney hung out at his hotel between 1 and 4 AM Saturday, so there's smoke, but the pic he posted is deceptive.