/jp/ - Otaku Culture

I'm confused with SSNI-548 especially the ending. I only know limited Japanese, from what I gather these 4 are friends with the main guy secretly has a crush on Yura. Then they end up banging but the main guy got the other girl while his friend got Yura. At least he got some sex, but still.
After that it seems the other guy and Yura continued banging each other, the other guy shown the main guy the footage and admit he has a feeling for Yura. The main guy hides his true feelings and congratulate his friends (mild NTR?). Then the last sex scene where the other guy and Yura casually had sex with the main guy in the room.
The ending shows that somehow the other guy ended up with that other girl in the group, leaving Yura alone. Doesn't seem Yura giving the main guy a chance though. If only I can understand the guy's monologue.

At first I thought these 4 are friends in open relationship free to bang in each other. But then the other guy said something about liking Yura more than the other girl, only to suddenly ditch Yura and went with that other girl instead. I'm overthinking porn again, I guess.