Rubber Oreo
The "Rubber Oreo" is the specific instance of the female "camel-toe" in tightly fitted workout pants. A classic Rubber Oreo will perfectly outline both outer labia and possibly inner labia wherein they resemble the edge of an Oreo cookie viewed from the side at a downward facing angle... then obviously wrapped tightly in rubber.
I was doing leg extensions at the gym and saw this girl's Rubber Oreo from behind during her set of Romanian Dead-lifts.