In truth, this is true of 98% of all porn films... It's not so much about "being real" as being convincing.
Just like all those "Collage guys being molested while sleeping vids" like gaycreeps or spyondudes
or the "Straight Seduction" stuff... and most "Amateur" films as well...
Yet, even if fake, it can be damn hot... Take "Stealth Breeding" by Treasure Island...
Well, The fact it is produced by TIM says fake right out of the gate... But assuming you don't know that it's by TIM. How many times have you hooked up off a website and had a full camera crew waiting when you got there? Some other small details clearly show it is fake, but it is currently still one of my all time favorites, because They Guys are hot, the top has a incredible cock, They use a condom at first (part of the premise...) and the top half way through pulls out and "Sneaks" the condom off, then finishes fucking the bottom BB, and shoots his load into the bottoms "unsuspecting" ass. It's still hot because they make it believable enough...
