Let's have a betrayal hentai thread. Essentially where one girl sells out another to be raped, but ends up being betrayed by the guys and also raped. Sadly, there's no actual tag for it, so my collection is only limited to 4 works at the minute.
So first up, pic related is Double Lesson Okawari, by Okumoto Yuuta. It pretty much fits the description to a t. Doesn't seem to be on panda, for some reason.
http://nhentai.net/g/121689/11/
Shinsei Reizoku Seitokai by Tokisana is pretty straightforward too. Blond sells out her student council president, pres gets back at her by having her gangraped and NTR'ing her boyfriend.
http://exhentai.org/g/646109/edc53323d1/
This one doesn't fit the description exactly, but the feeling is close enough. Glasses's friend follows her to a sex shop without realizing, ends up getting stripped and cummed on. No penetration for her though. This one's part of Mon-Mon Animal Girl by Sameda Koban, which also doesn't seem to be on panda.
http://nhentai.net/g/110792/
Finally, an Infinite Stratos doujin where China sells out her "friends" and her entire class to faceless men, in order to get Ichika for herself. But it's Fatalpulse, so things go bad for her.
http://exhentai.org/g/400920/5096a278b6/
This one isn't exactly a clear fit either, but the idea of a reversal of power is there. Kimi no Chin Chin Shameraseta Konyoku Onsen Hen has 2 girls going around humiliating men by winning various games against them, taking pictures of their dicks, and ends with the two having what they did come back at them. http://exhentai.org/g/176982/0ee3dbcd21/?p=2
Reversal of power probably fits this whole thing better I suppose. Is there a word for that in nip?
http://exhentai.org/g/801224/4750db042e/
I remember one where a younger sister sets up the older one to do porno. You know that one?
>>4189446
I dont but i have one similar to that its called shared love were one wife is cheating on the husband and her twin makes her into a cumdump for ntrĀ“r so she can be with the husband.
Dark Ping Pong Club.
It's pretty implicit unfortunately, very last page.