you have to see the scene and then you will change your mind about lube, my trusted son.
I've seen the scene too. I am more impressed with the way her ass looked (well her entire look) in the scene than the scene itself.
But from the looks of it...that wasn't lube (the kind that comes from tubes).
Also, if someone watches a Brea Bennett scene and can't tell she's cumming for real as hers are the most obvious on the planet (esp. her scene with Vega Vixen), I would say just give up on trying to tell anything about human beings ever.