Deliverance is completed and has optional swinging and wife sharing that does not delve into humiliation. There are a few scenes like that, but it is not the focus of the game.
Some LOP games (Living With Temptation, Club Velvet Rose) also have swinging and wife sharing, but it could turn into NTR if not handled carefully. However I think that the possibility to screw it up, actually makes the game better. These are sandbox games and usually have multiple expansions, sequels and remakes. Blind Date 3D is also from the same developers, but is actually a real-time 3D game (not too great graphics) and there are swinging scenes, cheating with best friend's wife, having a threesome with them and a wife-sharing scene with minimal humiliation for the friend.
There are also a few Netori games that feature swinging, cuckolding and humiliation, but the MC is actually the bull. Midlife Crisis, which was mentioned above had an extremely hot scene that could play out like that (MC is the bull and fucks his sister in front of her husband) or with minimal humiliation for the other guy. MC's wife could also be involved in a threesome or foursome, depending on the path. In the last update it introduced a new couple to swing with. But then development stopped...
Another interesting game is Lost in Paradise, where there is a mild sharing path of the MC's wife, a hardcore cuckolding path, as well as a Netori path with the girlfriend of MC's best friend. The developer specializes in NTR though.
