I'm with you totally. I'd love to swap and have a group scene with Darius and his GF, if she existed. Absolutely! Sharing, swapping, messy, sweaty, cum covered sex is fantastic, so long as everyone is on board. Its the stealing and especially the shaming that I'm not into. Cheating can be sexy if done right, but I never want the MC to feel like a loser or get hurt.And indeed, it very much did start out closer to what you're describing - early on Val has her hijinx with darius, or shuts him down, then randy, and meanwhile MC can be messing around with Alyssa along with shenanigans with his family.
The point where it starts feeling more like "adventerous couple" is when the dad moves in, then at the current endgame conclusion it goes totally off the rails into "bull bunny cuck" land regardless of previous choices.
Totally, some of my fav scenes were the foursomes like mc-val-alyssa-dad or when you invite the coworkers over to the pool.
I dont just hate darius because I dislike IR sharing games; whenever he enters a scene the swinging probability plummets. (actually the latter probably contributes to the former ). If darius had a girlfriend and they set up some party night where val and mc both got wild I'd be all for it.
And I gave up on The Adventerous Couple when it really turned in that direction too, and haven't gone back. I don't just want to watch the cuck experience, even if he's signing off on all of it. I want the MC in on the action with the wife/gf, or otherwise getting it on with someone else while she's out there getting fucked by another man.