Can anyone explain weird markings after a spray tan I did?

[tanforeverbrown]

I honestly don't think it's from sweat. It looks like dry skin. It happens on me around my armpits if I spray too much and they are dry. If she bent forward how would it crease...If she bent her legs back?

She was facing me, having already sprayed the back of her, including the backs of her knees, so this would have still been wet, and to get the wrinkles around the front of her knees she bent her knees forward towards me, which means this would have created a crease in the back of her (damp) knees which must have caused those marks