Probably because they had already orgasm before the performance and or during it. If there was never any ejaculation or penetration shown then it was not hardcore porn. It would be just softcore porn.
I love how this show wasn’t shy about showing the pussy both from the front and the behind. You also saw dick sometimes too and none of these guys had hard ons when you saw dick. Even in this scene at the end you see dudes dick and he’s flaccid. How did these guys have such control?
Seeing Dena on top thrusting is just instant boner material. How did these guys not have the biggest hard ons in scenes with her doing that. It would have been so tempting to slip it in.