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[DeSade]

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[giga-ganon]

in the NGOD serie, a lot of time the husband just stay with the wife and have to endure seeing her having sex with the other guy every day

 

[DeSade]

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[loleechero]

If, for example, anyone knows of any movies like I described above that are set during any type of gameshow or challenge, those would be great.

Those transparent bath tub game, SDMU 189, SDMT 802, IENE 560, SDMU 724, SDMU 763, and several more (Just search its director: Chain Shuu)
I always thought an idea where a man must watch their girls, dressed in various costume (wedding dress would be the best), and must fuck those creepy old man or otakus for the prize.

Lastly, anything in this genre that incorporates some weird/outlandish plot element like time stopping or hypnosis or mind control or fictional alternate realities where there's no taboo surrounding sex and everyone just walks up and fucks who they want (I've seen a few of these), all that is welcome.

Try RCT 887, closest in my mind as you describe. Basically some time stopper guy fuck newly wedded bride.
NTR in wedding dress is sooo hot IMO. Definitely needs moar

 

[DeSade]

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[loleechero]

Thanks for the recommendations. Do you know any of the codes for the transparent bathtub game ones? I remember seeing one of those awhile back but I haven't come across it since.

I don't know, but I believe its belongs to RCT or IENE. I never really look for it, its just pop up from some random streaming site's recommendation.
PS. The NTR part is only one scene at the end.