JAV Porn – How did they manage to produce such an enormous amount of semen in this film?

I’ve seen some “ROOKIE 世界一” movies and I’m really curious how they achieve such massive ejaculations. I suspect that they fitted a fake penis over the real one, and the real penis is tucked inside that huge prop scrotum, with the fake semen being expelled from the prop scrotum. That’s my guess. I’d like to hear everyone’s thoughts and opinions