Here is the Japanese Wikipedia article about it translated into English: http://translate.google.com/transla...7%B2%BE&hl=en&langpair=auto|en&tbb=1&ie=UTF-8
It discusses the fake creampies at length. Some western porn uses it too, such as the Creampie Angels series. You can often tell because it looks fake - too much of it, too thick. They usually cut away so they can pump it in too. In JAV sometimes you can see the condoms as well if you look closely, even with the mosaic. In fact a few times previously censored movies have leaked out uncensored, complete with the fake creampies and visible condoms.
Recently more and more JAV videos have started including proof that the nakadashi is real, since it is now well known that 90% are fake. This typically involves the guy pulling out and ejaculating visibly a bit, then re-inserting for the remainder. Sometimes they will show going from a blowjob to vaginal sex without any cut to imply that no condom was put on, but of course the blowjob itself could have been covered.
It discusses the fake creampies at length. Some western porn uses it too, such as the Creampie Angels series. You can often tell because it looks fake - too much of it, too thick. They usually cut away so they can pump it in too. In JAV sometimes you can see the condoms as well if you look closely, even with the mosaic. In fact a few times previously censored movies have leaked out uncensored, complete with the fake creampies and visible condoms.
Recently more and more JAV videos have started including proof that the nakadashi is real, since it is now well known that 90% are fake. This typically involves the guy pulling out and ejaculating visibly a bit, then re-inserting for the remainder. Sometimes they will show going from a blowjob to vaginal sex without any cut to imply that no condom was put on, but of course the blowjob itself could have been covered.